leetcode-javascript | LeetCode JavaScript Thinking（1-1312）

leetcode-javascript is a JavaScript library. leetcode-javascript has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

利用Map缓存, key = target - nums[index], val = index. 类似十进制的运算, 从后面往前撸, 大于9要进一位, 麻烦的是要在链表中计算. 5: Longest Palindromic Substring [Medium] ] . 设定left, right两个index, 当s[left] === s[right], 则是回文, 向外侧递增, 当 right - left > s.length - index 循环可以退出 另外pivot有两种情况, 如果s长度是偶数就没有pivot. ZigZag有如下规律, 当n=3的时候Y坐标为[0,1,2,1], 当n=4的时候Y坐标为[0,1,2,3,2,1], 按照这个规律像俄罗斯方块一样累加再拼接即可. 用parseInt方法处理, 数字范围在INT_MAX在 [2 ** 32 -1, -(2 ** 32)] 之间. 简易的办法是转成数组后reverse, 如果等于本身就是回文, 另一个办法是遍历从两边(0, length - 1)向内开始遍历, 参考longest-palindromic-substring. 类型求最大面积, x坐标=索引距离, y坐标=两根柱子最小值, 从两边向内收缩即可. 首先进行排序, 三个游标j = 0; k = j + 1; l = length -1, 其中jl向内走, 如果重叠了进位, 把三个数相加与target对比. 核心思想和上题基本一致, 用Math.abs(sum - target)计算距离, 存closest的值. 保存一个referenceArray的引用, 遍历完成后找到目标，通过prev.next = prev.next.next即可删除. {[()]}是对称性的, 所以两两之后等于5, 声明一个数组, 遍历时如果和为5就pop, 否则push. 直接的思路是全排序去重，其中左'(' 与 右')' 是固定的，可以减少一部分复杂度，更简单的方法 是不断的拼接递归，直到左右计数器剩余为0退出，由于必须是‘)’结尾，需要设条件right > left. 设需要交换的两个点为 head 和 next，head 连接后面交换完成的子链表，next 连接 head，完成交换. 遍历时用当前值和前一个值对比, 如果不相等, 用当前值替换掉前一个值, ++计数器, 结果等于nums.length - 计数器. 不能用乘除摩来实现除的方法, 所以用二分查找和 >> << 位运算实现. [30: Substring with Concatenation of All Words [Hard]]. [32: Longest Valid Parentheses [Hard]]. [33: Search in Rotated Sorted Array [Medium]]. [34: Find First and Last Position of Element in Sorted Array [Medium]]. 用二分查找找到目标, low <= target <= high. [36: Valid Sudoku [Medium]]. [37: Sudoku Solver [Hard]]. 难点不是题目算法, 是题目的理解上, 结果找了中文版才醍醐灌顶 其实就是用上一次的结果来计算, 其中, 第一个是量词/频次, 第二个是值 1 就是1 = 1 2 一个1 = 11 3 两个1 = 21 4 一个2和一个1 = 1211 5 一个1一个2两个1 = 111221 ... 以此类推 ... emm,,, 递归就可以了. [40: Combination Sum II [Medium]]. [41: First Missing Positive [Hard]]. [42: Trapping Rain Water [Hard]]. [43: Multiply Strings [Medium]]. [44: Wildcard Matching [Hard]]. [45: Jump Game II [Hard]]. [47: Permutations II [Medium]]. [48: Rotate Image [Medium]]. [49: Group Anagrams [Medium]]. [50: Pow(x, n) [Medium]]. [52: N-Queens II [Hard]]. [54: Spiral Matrix [Medium]]. [55: Jump Game [Medium]]. [56: Merge Intervals [Medium]]. [57: Insert Interval [Hard]]. 用正则效率太低, 另一个办法是逆序遍历, 当不为空的时候累加长度, 再遇到空格退出. [59: Spiral Matrix II [Medium]]. [60: Permutation Sequence [Medium]]. [61: Rotate List [Medium]]. [62: Unique Paths [Medium]]. [63: Unique Paths II [Medium]]. [64: Minimum Path Sum [Medium]]. [65: Valid Number [Hard]]. [68: Text Justification [Hard]]. 也是一个二分查找, 范围是 [0, Math.floor(Math.sqrt(Number.MAX_SAFE_INTEGER))]之间, 退出条件是 high - low <= 1, 所以floor的low + high的中间值为结果. 很经典的上台阶问题, 网上的讨论已经非常多了, 本质是一个斐波拉契数列的经典实例, 后值等于当前值加前一个值的和"n = (n-1）(n-2)", 由于递归的时候会重复计算, 所以加上缓存可以解决性能问题. [71: Simplify Path [Medium]]. [72: Edit Distance [Hard]]. [73: Set Matrix Zeroes [Medium]]. [74: Search a 2D Matrix [Medium]]. [75: Sort Colors [Medium]]. [76: Minimum Window Substring [Hard]]. [79: Word Search [Medium]]. [80: Remove Duplicates from Sorted Array II [Medium]]. [81: Search in Rotated Sorted Array II [Medium]]. [82: Remove Duplicates from Sorted List II [Medium]]. [84: Largest Rectangle in Histogram [Hard]]. [85: Maximal Rectangle [Hard]]. [86: Partition List [Medium]]. [87: Scramble String [Hard]]. [89: Gray Code [Medium]]. [90: Subsets II [Medium]]. [91: Decode Ways [Medium]]. [92: Reverse Linked List II [Medium]]. [93: Restore IP Addresses [Medium]]. [94: Binary Tree Inorder Traversal [Medium]]. [95: Unique Binary Search Trees II [Medium]]. [96: Unique Binary Search Trees [Medium]]. [97: Interleaving String [Hard]]. [98: Validate Binary Search Tree [Medium]]. [99: Recover Binary Search Tree [Hard]]. [101: Symmetric Tree [Easy]]. 用A，B两个节点left, right两节点交错递归对比，即(A.left, B.right) (B.left, A.right), 当节点没有子节点并且值一样时退出. [102: Binary Tree Level Order Traversal [Medium]]. [103: Binary Tree Zigzag Level Order Traversal [Medium]]. [104: Maximum Depth of Binary Tree [Easy]]. [105: Construct Binary Tree from Preorder and Inorder Traversal [Medium]]. [106: Construct Binary Tree from Inorder and Postorder Traversal [Medium]]. [107: Binary Tree Level Order Traversal II [Easy]]. [108: Convert Sorted Array to Binary Search Tree [Easy]]. [109: Convert Sorted List to Binary Search Tree [Medium]]. [110: Balanced Binary Tree [Easy]]. [111: Minimum Depth of Binary Tree [Easy]]. [112: Path Sum [Easy]]. [113: Path Sum II [Medium]]. [114: Flatten Binary Tree to Linked List [Medium]]. [115: Distinct Subsequences [Hard]]. [116: Populating Next Right Pointers in Each Node [Medium]]. [117: Populating Next Right Pointers in Each Node II [Medium]]. [118: Pascal's Triangle [Easy]]. [119: Pascal's Triangle II [Easy]]. [121: Best Time to Buy and Sell Stock [Easy]]. [122: Best Time to Buy and Sell Stock II [Easy]]. [123: Best Time to Buy and Sell Stock III [Hard]]. [124: Binary Tree Maximum Path Sum [Hard]]. [125: Valid Palindrome [Easy]]. [126: Word Ladder II [Hard]]. [127: Word Ladder [Medium]]. [128: Longest Consecutive Sequence [Hard]]. [129: Sum Root to Leaf Numbers [Medium]]. [130: Surrounded Regions [Medium]]. [131: Palindrome Partitioning [Medium]]. [132: Palindrome Partitioning II [Hard]]. [133: Clone Graph [Medium]]. [134: Gas Station [Medium]]. [136: Single Number [Easy]]. [137: Single Number II [Medium]]. [138: Copy List with Random Pointer [Medium]]. [139: Word Break [Medium]]. [140: Word Break II [Hard]]. [141: Linked List Cycle [Easy]]. [142: Linked List Cycle II [Medium]]. [143: Reorder List [Medium]]. [144: Binary Tree Preorder Traversal [Medium]]. [145: Binary Tree Postorder Traversal [Hard]]. [146: LRU Cache [Medium]]. [147: Insertion Sort List [Medium]]. [148: Sort List [Medium]]. [149: Max Points on a Line [Hard]]. [150: Evaluate Reverse Polish Notation [Medium]]. [151: Reverse Words in a String [Medium]]. [152: Maximum Product Subarray [Medium]]. [153: Find Minimum in Rotated Sorted Array [Medium]]. [154: Find Minimum in Rotated Sorted Array II [Hard]]. [155: Min Stack [Easy]]. [156: Binary Tree Upside Down [Medium]]. [157: Read N Characters Given Read4 [Easy]]. [158: Read N Characters Given Read4 II - Call multiple times [Hard]]. [159: Longest Substring with At Most Two Distinct Characters [Medium]]. [160: Intersection of Two Linked Lists [Easy]]. [161: One Edit Distance [Medium]]. [162: Find Peak Element [Medium]]. [163: Missing Ranges [Medium]]. [164: Maximum Gap [Hard]]. [165: Compare Version Numbers [Medium]]. [166: Fraction to Recurring Decimal [Medium]]. [167: Two Sum II - Input array is sorted [Easy]]. [168: Excel Sheet Column Title [Easy]]. [169: Majority Element [Easy]]. [170: Two Sum III - Data structure design [Easy]]. [171: Excel Sheet Column Number [Easy]]. [172: Factorial Trailing Zeroes [Easy]]. [173: Binary Search Tree Iterator [Medium]]. [174: Dungeon Game [Hard]]. [175: Combine Two Tables [Easy]]. [176: Second Highest Salary [Easy]]. [177: Nth Highest Salary [Medium]]. [178: Rank Scores [Medium]]. [179: Largest Number [Medium]]. [180: Consecutive Numbers [Medium]]. [181: Employees Earning More Than Their Managers [Easy]]. [182: Duplicate Emails [Easy]]. [183: Customers Who Never Order [Easy]]. [184: Department Highest Salary [Medium]]. [185: Department Top Three Salaries [Hard]]. [186: Reverse Words in a String II [Medium]]. [187: Repeated DNA Sequences [Medium]]. [188: Best Time to Buy and Sell Stock IV [Hard]]. [189: Rotate Array [Easy]]. [190: Reverse Bits [Easy]]. [191: Number of 1 Bits [Easy]]. [192: Word Frequency [Medium]]. [193: Valid Phone Numbers [Easy]]. [194: Transpose File [Medium]]. [195: Tenth Line [Easy]]. [196: Delete Duplicate Emails [Easy]]. [197: Rising Temperature [Easy]]. [198: House Robber [Easy]]. [199: Binary Tree Right Side View [Medium]]. [200: Number of Islands [Medium]]. [201: Bitwise AND of Numbers Range [Medium]]. [202: Happy Number [Easy]]. [203: Remove Linked List Elements [Easy]]. [204: Count Primes [Easy]]. [205: Isomorphic Strings [Easy]]. [207: Course Schedule [Medium]]. [208: Implement Trie (Prefix Tree) [Medium]]. [209: Minimum Size Subarray Sum [Medium]]. [210: Course Schedule II [Medium]]. [211: Add and Search Word - Data structure design [Medium]]. [212: Word Search II [Hard]]. [213: House Robber II [Medium]]. [214: Shortest Palindrome [Hard]]. [215: Kth Largest Element in an Array [Medium]]. [216: Combination Sum III [Medium]]. [217: Contains Duplicate [Easy]]. [218: The Skyline Problem [Hard]]. [219: Contains Duplicate II [Easy]]. [220: Contains Duplicate III [Medium]]. [221: Maximal Square [Medium]]. [222: Count Complete Tree Nodes [Medium]]. [223: Rectangle Area [Medium]]. [224: Basic Calculator [Hard]]. [225: Implement Stack using Queues [Easy]]. [226: Invert Binary Tree [Easy]]. [227: Basic Calculator II [Medium]]. [228: Summary Ranges [Medium]]. [229: Majority Element II [Medium]]. [230: Kth Smallest Element in a BST [Medium]]. [231: Power of Two [Easy]]. [232: Implement Queue using Stacks [Easy]]. [233: Number of Digit One [Hard]]. [234: Palindrome Linked List [Easy]]. [235: Lowest Common Ancestor of a Binary Search Tree [Easy]]. [236: Lowest Common Ancestor of a Binary Tree [Medium]]. [237: Delete Node in a Linked List [Easy]]. [238: Product of Array Except Self [Medium]]. [239: Sliding Window Maximum [Hard]]. [240: Search a 2D Matrix II [Medium]]. [241: Different Ways to Add Parentheses [Medium]]. [242: Valid Anagram [Easy]]. [243: Shortest Word Distance [Easy]]. [244: Shortest Word Distance II [Medium]]. [245: Shortest Word Distance III [Medium]]. [246: Strobogrammatic Number [Easy]]. [247: Strobogrammatic Number II [Medium]]. [248: Strobogrammatic Number III [Hard]]. [249: Group Shifted Strings [Medium]]. [250: Count Univalue Subtrees [Medium]]. [251: Flatten 2D Vector [Medium]]. [252: Meeting Rooms [Easy]]. [253: Meeting Rooms II [Medium]]. [254: Factor Combinations [Medium]]. [255: Verify Preorder Sequence in Binary Search Tree [Medium]]. [256: Paint House [Easy]]. [257: Binary Tree Paths [Easy]]. [258: Add Digits [Easy]]. [259: 3Sum Smaller [Medium]]. [260: Single Number III [Medium]]. [261: Graph Valid Tree [Medium]]. [262: Trips and Users [Hard]]. [263: Ugly Number [Easy]]. [264: Ugly Number II [Medium]]. [265: Paint House II [Hard]]. [266: Palindrome Permutation [Easy]]. [267: Palindrome Permutation II [Medium]]. [268: Missing Number [Easy]]. [269: Alien Dictionary [Hard]]. [270: Closest Binary Search Tree Value [Easy]]. [271: Encode and Decode Strings [Medium]]. [272: Closest Binary Search Tree Value II [Hard]]. [273: Integer to English Words [Hard]]. [275: H-Index II [Medium]]. [276: Paint Fence [Easy]]. [277: Find the Celebrity [Medium]]. [278: First Bad Version [Easy]]. [279: Perfect Squares [Medium]]. [280: Wiggle Sort [Medium]]. [281: Zigzag Iterator [Medium]]. [282: Expression Add Operators [Hard]]. [283: Move Zeroes [Easy]]. [284: Peeking Iterator [Medium]]. [285: Inorder Successor in BST [Medium]]. [286: Walls and Gates [Medium]]. [287: Find the Duplicate Number [Medium]]. [288: Unique Word Abbreviation [Medium]]. [289: Game of Life [Medium]]. [290: Word Pattern [Easy]]. [291: Word Pattern II [Hard]]. [292: Nim Game [Easy]]. [293: Flip Game [Easy]]. [294: Flip Game II [Medium]]. [295: Find Median from Data Stream [Hard]]. [296: Best Meeting Point [Hard]]. [297: Serialize and Deserialize Binary Tree [Hard]]. [298: Binary Tree Longest Consecutive Sequence [Medium]]. [299: Bulls and Cows [Easy]]. [300: Longest Increasing Subsequence [Medium]]. [Remo301: ve Invalid Parentheses [Hard]]. [302: Smallest Rectangle Enclosing Black Pixels [Hard]]. [303: Range Sum Query - Immutable [Easy]]. [304: Range Sum Query 2D - Immutable [Medium]]. [305: Number of Islands II [Hard]]. [306: Additive Number [Medium]]. [307: Range Sum Query - Mutable [Medium]]. [308: Range Sum Query 2D - Mutable [Hard]]. [309: Best Time to Buy and Sell Stock with Cooldown [Medium]]. [310: Minimum Height Trees [Medium]]. [311: Sparse Matrix Multiplication [Medium]]. [312: Burst Balloons [Hard]]. [313: Super Ugly Number [Medium]]. [314: Binary Tree Vertical Order Traversal [Medium]]. [315: Count of Smaller Numbers After Self [Hard]]. [316: Remove Duplicate Letters [Hard]]. [317: Shortest Distance from All Buildings [Hard]]. [318: Maximum Product of Word Lengths [Medium]]. [319: Bulb Switcher [Medium]]. [320: Generalized Abbreviation [Medium]]. [321: Create Maximum Number [Hard]]. [322: Coin Change [Medium]]. [323: Number of Connected Components in an Undirected Graph [Medium]]. [324: Wiggle Sort II [Medium]]. [325: Maximum Size Subarray Sum Equals k [Medium]]. [326: Power of Three [Easy]]. [327: Count of Range Sum [Hard]]. [328: Odd Even Linked List [Medium]]. [329: Longest Increasing Path in a Matrix [Hard]]. [330: Patching Array [Hard]]. [331: Verify Preorder Serialization of a Binary Tree [Medium]]. [332: Reconstruct Itinerary [Medium]]. [333: Largest BST Subtree [Medium]]. [334: Increasing Triplet Subsequence [Medium]]. [335: Self Crossing [Hard]]. [336: Palindrome Pairs [Hard]]. [337: House Robber III [Medium]]. [338: Counting Bits [Medium]]. [339: Nested List Weight Sum [Easy]]. [340: Longest Substring with At Most K Distinct Characters [Hard]]. [341: Flatten Nested List Iterator [Medium]]. [342: Power of Four [Easy]]. [343: Integer Break [Medium]]. [344: Reverse String [Easy]]. [345: Reverse Vowels of a String [Easy]]. [346: Moving Average from Data Stream [Easy]]. [347: Top K Frequent Elements [Medium]]. [348: Design Tic-Tac-Toe [Medium]]. [349: Intersection of Two Arrays [Easy]]. [350: Intersection of Two Arrays II [Easy]]. [351: Android Unlock Patterns [Medium]]. [352: Data Stream as Disjoint Intervals [Hard]]. [353: Design Snake Game [Medium]]. [354: Russian Doll Envelopes [Hard]]. [355: Design Twitter [Medium]]. [356: Line Reflection [Medium]]. [357: Count Numbers with Unique Digits [Medium]]. [358: Rearrange String k Distance Apart [Hard]]. [359: Logger Rate Limiter [Easy]]. [360: Sort Transformed Array [Medium]]. [361: Bomb Enemy [Medium]]. [362: Design Hit Counter [Medium]]. [363: Max Sum of Rectangle No Larger Than K [Hard]]. [364: Nested List Weight Sum II [Medium]]. [365: Water and Jug Problem [Medium]]. [366: Find Leaves of Binary Tree [Medium]]. [367: Valid Perfect Square [Easy]]. [368: Largest Divisible Subset [Medium]]. [369: Plus One Linked List [Medium]]. [370: Range Addition [Medium]]. [371: Sum of Two Integers [Easy]]. [372: Super Pow [Medium]]. [373: Find K Pairs with Smallest Sums [Medium]]. [374: Guess Number Higher or Lower [Easy]]. [375: Guess Number Higher or Lower II [Medium]]. [376: Wiggle Subsequence [Medium]]. [377: Combination Sum IV [Medium]]. [378: Kth Smallest Element in a Sorted Matrix [Medium]]. [379: Design Phone Directory [Medium]]. [380: Insert Delete GetRandom O(1) [Medium]]. [381: Insert Delete GetRandom O(1) - Duplicates allowed [Hard]]. [382: Linked List Random Node [Medium]]. [383: Ransom Note [Easy]]. [384: Shuffle an Array [Medium]]. [385: Mini Parser [Medium]]. [386: Lexicographical Numbers [Medium]]. [387: First Unique Character in a String [Easy]]. [388: Longest Absolute File Path [Medium]]. [389: Find the Difference [Easy]]. [390: Elimination Game [Medium]]. [391: Perfect Rectangle [Hard]]. [392: Is Subsequence [Easy]]. [393: UTF-8 Validation [Medium]]. [394: Decode String [Medium]]. [395: Longest Substring with At Least K Repeating Characters [Medium]]. [396: Rotate Function [Medium]]. [397: Integer Replacement [Medium]]. [398: Random Pick Index [Medium]]. [399: Evaluate Division [Medium]]. [400: Nth Digit ]]. [Bina401: ry Watch [Easy]]. [402: Remove K Digits [Medium]]. [403: Frog Jump [Hard]]. [404: Sum of Left Leaves [Easy]]. [405: Convert a Number to Hexadecimal [Easy]]. [406: Queue Reconstruction by Height [Medium]]. [407: Trapping Rain Water II [Hard]]. [408: Valid Word Abbreviation [Easy]]. [409: Longest Palindrome [Easy]]. [410: Split Array Largest Sum [Hard]]. [411: Minimum Unique Word Abbreviation [Hard]]. [412: Fizz Buzz [Easy]]. [413: Arithmetic Slices [Medium]]. [414: Third Maximum Number [Easy]]. [415: Add Strings [Easy]]. [416: Partition Equal Subset Sum [Medium]]. [417: Pacific Atlantic Water Flow [Medium]]. [418: Sentence Screen Fitting [Medium]]. [419: Battleships in a Board [Medium]]. [420: Strong Password Checker [Hard]]. [421: Maximum XOR of Two Numbers in an Array [Medium]]. [422: Valid Word Square [Easy]]. [423: Reconstruct Original Digits from English [Medium]]. [424: Longest Repeating Character Replacement [Medium]]. [425: Word Squares [Hard]]. [426: Convert Binary Search Tree to Sorted Doubly Linked List [Medium]]. [427: Construct Quad Tree [Medium]]. [428: Serialize and Deserialize N-ary Tree [Hard]]. [429: N-ary Tree Level Order Traversal [Medium]]. [430: Flatten a Multilevel Doubly Linked List [Medium]]. [431: Encode N-ary Tree to Binary Tree [Hard]]. [432: All O`one Data Structure [Hard]]. [433: Minimum Genetic Mutation [Medium]]. [434: Number of Segments in a String [Easy]]. [435: Non-overlapping Intervals [Medium]]. [436: Find Right Interval [Medium]]. [437: Path Sum III [Easy]]. [438: Find All Anagrams in a String [Medium]]. [439: Ternary Expression Parser [Medium]]. [440: K-th Smallest in Lexicographical Order [Hard]]. [441: Arranging Coins [Easy]]. [442: Find All Duplicates in an Array [Medium]]. [443: String Compression [Easy]]. [444: Sequence Reconstruction [Medium]]. [445: Add Two Numbers II [Medium]]. [446: Arithmetic Slices II - Subsequence [Hard]]. [447: Number of Boomerangs [Easy]]. [448: Find All Numbers Disappeared in an Array [Easy]]. [449: Serialize and Deserialize BST [Medium]]. [450: Delete Node in a BST [Medium]]. [451: Sort Characters By Frequency [Medium]]. [452: Minimum Number of Arrows to Burst Balloons [Medium]]. [453: Minimum Moves to Equal Array Elements [Easy]]. [454: 4Sum II [Medium]]. [455: Assign Cookies [Easy]]. [456: 132 Pattern [Medium]]. [457: Circular Array Loop [Medium]]. [458: Poor Pigs [Hard]]. [459: Repeated Substring Pattern [Easy]]. [460: LFU Cache [Hard]]. [461: Hamming Distance [Easy]]. [462: Minimum Moves to Equal Array Elements II [Medium]]. [463: Island Perimeter [Easy]]. [464: Can I Win [Medium]]. [465: Optimal Account Balancing [Hard]]. [466: Count The Repetitions [Hard]]. [467: Unique Substrings in Wraparound String [Medium]]. [468: Validate IP Address [Medium]]. [469: Convex Polygon [Medium]]. [470: Implement Rand10() Using Rand7() [Medium]]. [471: Encode String with Shortest Length [Hard]]. [472: Concatenated Words [Hard]]. [473: Matchsticks to Square [Medium]]. [474: Ones and Zeroes [Medium]]. [476: Number Complement [Easy]]. [477: Total Hamming Distance [Medium]]. [478: Generate Random Point in a Circle [Medium]]. [479: Largest Palindrome Product [Hard]]. [480: Sliding Window Median [Hard]]. [481: Magical String [Medium]]. [482: License Key Formatting [Easy]]. [483: Smallest Good Base [Hard]]. [484: Find Permutation [Medium]]. [485: Max Consecutive Ones [Easy]]. [486: Predict the Winner [Medium]]. [487: Max Consecutive Ones II [Medium]]. [488: Zuma Game [Hard]]. [489: Robot Room Cleaner [Hard]]. [490: The Maze [Medium]]. [491: Increasing Subsequences [Medium]]. [492: Construct the Rectangle [Easy]]. [493: Reverse Pairs [Hard]]. [494: Target Sum [Medium]]. [495: Teemo Attacking [Medium]]. [496: Next Greater Element I [Easy]]. [497: Random Point in Non-overlapping Rectangles [Medium]]. [498: Diagonal Traverse [Medium]]. [499: The Maze III [Hard]]. [500: Keyboard Row [Easy]]. [Find501: Mode in Binary Search Tree [Easy]]. [503: Next Greater Element II [Medium]]. [504: Base 7 [Easy]]. [505: The Maze II [Medium]]. [506: Relative Ranks [Easy]]. [507: Perfect Number [Easy]]. [508: Most Frequent Subtree Sum [Medium]]. [509: Fibonacci Number [Easy]]. [510: Inorder Successor in BST II [Medium]]. [511: Game Play Analysis I [Easy]]. [512: Game Play Analysis II [Easy]]. [513: Find Bottom Left Tree Value [Medium]]. [514: Freedom Trail [Hard]]. [515: Find Largest Value in Each Tree Row [Medium]]. [516: Longest Palindromic Subsequence [Medium]]. [517: Super Washing Machines [Hard]]. [518: Coin Change 2 [Medium]]. [519: Random Flip Matrix [Medium]]. [520: Detect Capital [Easy]]. [521: Longest Uncommon Subsequence I [Easy]]. [522: Longest Uncommon Subsequence II [Medium]]. [523: Continuous Subarray Sum [Medium]]. [524: Longest Word in Dictionary through Deleting [Medium]]. [525: Contiguous Array [Medium]]. [526: Beautiful Arrangement [Medium]]. [527: Word Abbreviation [Hard]]. [528: Random Pick with Weight [Medium]]. [530: Minimum Absolute Difference in BST [Easy]]. [531: Lonely Pixel I [Medium]]. [532: K-diff Pairs in an Array [Easy]]. [533: Lonely Pixel II [Medium]]. [534: Game Play Analysis III [Medium]]. [535: Encode and Decode TinyURL [Medium]]. [536: Construct Binary Tree from String [Medium]]. [537: Complex Number Multiplication [Medium]]. [538: Convert BST to Greater Tree [Easy]]. [539: Minimum Time Difference [Medium]]. [540: Single Element in a Sorted Array [Medium]]. [541: Reverse String II [Easy]]. [542: 01 Matrix [Medium]]. [543: Diameter of Binary Tree [Easy]]. [544: Output Contest Matches [Medium]]. [545: Boundary of Binary Tree [Medium]]. [546: Remove Boxes [Hard]]. [547: Friend Circles [Medium]]. [548: Split Array with Equal Sum [Medium]]. [549: Binary Tree Longest Consecutive Sequence II [Medium]]. [550: Game Play Analysis IV [Medium]]. [551: Student Attendance Record I [Easy]]. [552: Student Attendance Record II [Hard]]. [553: Optimal Division [Medium]]. [554: Brick Wall [Medium]]. [555: Split Concatenated Strings [Medium]]. [556: Next Greater Element III [Medium]]. [557: Reverse Words in a String III [Easy]]. [558: Quad Tree Intersection [Easy]]. [559: Maximum Depth of N-ary Tree [Easy]]. [560: Subarray Sum Equals K [Medium]]. [561: Array Partition I [Easy]]. [562: Longest Line of Consecutive One in Matrix [Medium]]. [563: Binary Tree Tilt [Easy]]. [564: Find the Closest Palindrome [Hard]]. [565: Array Nesting [Medium]]. [566: Reshape the Matrix [Easy]]. [567: Permutation in String [Medium]]. [568: Maximum Vacation Days [Hard]]. [569: Median Employee Salary [Hard]]. [570: Managers with at Least 5 Direct Reports [Medium]]. [571: Find Median Given Frequency of Numbers [Hard]]. [572: Subtree of Another Tree [Easy]]. [573: Squirrel Simulation [Medium]]. [574: Winning Candidate [Medium]]. [575: Distribute Candies [Easy]]. [576: Out of Boundary Paths [Medium]]. [577: Employee Bonus [Easy]]. [578: Get Highest Answer Rate Question [Medium]]. [579: Find Cumulative Salary of an Employee [Hard]]. [580: Count Student Number in Departments [Medium]]. [581: Shortest Unsorted Continuous Subarray [Easy]]. [582: Kill Process [Medium]]. [583: Delete Operation for Two Strings [Medium]]. [584: Find Customer Referee [Easy]]. [585: Investments in 2016 [Medium]]. [586: Customer Placing the Largest Number of Orders [Easy]]. [587: Erect the Fence [Hard]]. [588: Design In-Memory File System [Hard]]. [589: N-ary Tree Preorder Traversal [Easy]]. [590: N-ary Tree Postorder Traversal [Easy]]. [591: Tag Validator [Hard]]. [592: Fraction Addition and Subtraction [Medium]]. [593: Valid Square [Medium]]. [594: Longest Harmonious Subsequence [Easy]]. [595: Big Countries [Easy]]. [596: Classes More Than 5 Students [Easy]]. [597: Friend Requests I: Overall Acceptance Rate [Easy]]. [598: Range Addition II [Easy]]. [599: Minimum Index Sum of Two Lists [Easy]]. [600: Non-negative Integers without Consecutive Ones [Hard]]. [Huma601: n Traffic of Stadium [Hard]]. [602: Friend Requests II: Who Has the Most Friends [Medium]]. [603: Consecutive Available Seats [Easy]]. [604: Design Compressed String Iterator [Easy]]. [605: Can Place Flowers [Easy]]. [606: Construct String from Binary Tree [Easy]]. [607: Sales Person [Easy]]. [608: Tree Node [Medium]]. [609: Find Duplicate File in System [Medium]]. [610: Triangle Judgement [Easy]]. [611: Valid Triangle Number [Medium]]. [612: Shortest Distance in a Plane [Medium]]. [613: Shortest Distance in a Line [Easy]]. [614: Second Degree Follower [Medium]]. [615: Average Salary: Departments VS Company [Hard]]. [616: Add Bold Tag in String [Medium]]. [617: Merge Two Binary Trees [Easy]]. [618: Students Report By Geography [Hard]]. [619: Biggest Single Number [Easy]]. [620: Not Boring Movies [Easy]]. [621: Task Scheduler [Medium]]. [622: Design Circular Queue [Medium]]. [623: Add One Row to Tree [Medium]]. [624: Maximum Distance in Arrays [Easy]]. [625: Minimum Factorization [Medium]]. [626: Exchange Seats [Medium]]. [627: Swap Salary [Easy]]. [628: Maximum Product of Three Numbers [Easy]]. [629: K Inverse Pairs Array [Hard]]. [630: Course Schedule III [Hard]]. [631: Design Excel Sum Formula [Hard]]. [632: Smallest Range Covering Elements from K Lists [Hard]]. [633: Sum of Square Numbers [Easy]]. [634: Find the Derangement of An Array [Medium]]. [635: Design Log Storage System [Medium]]. [636: Exclusive Time of Functions [Medium]]. [637: Average of Levels in Binary Tree [Easy]]. [638: Shopping Offers [Medium]]. [639: Decode Ways II [Hard]]. [640: Solve the Equation [Medium]]. [641: Design Circular Deque [Medium]]. [642: Design Search Autocomplete System [Hard]]. [643: Maximum Average Subarray I [Easy]]. [644: Maximum Average Subarray II [Hard]]. [645: Set Mismatch [Easy]]. [646: Maximum Length of Pair Chain [Medium]]. [647: Palindromic Substrings [Medium]]. [648: Replace Words [Medium]]. [649: Dota2 Senate [Medium]]. [650: 2 Keys Keyboard [Medium]]. [651: 4 Keys Keyboard [Medium]]. [652: Find Duplicate Subtrees [Medium]]. [653: Two Sum IV - Input is a BST [Easy]]. [654: Maximum Binary Tree [Medium]]. [655: Print Binary Tree [Medium]]. [656: Coin Path [Hard]]. [657: Robot Return to Origin [Easy]]. [658: Find K Closest Elements [Medium]]. [659: Split Array into Consecutive Subsequences [Medium]]. [660: Remove 9 [Hard]]. [661: Image Smoother [Easy]]. [662: Maximum Width of Binary Tree [Medium]]. [663: Equal Tree Partition [Medium]]. [664: Strange Printer [Hard]]. [665: Non-decreasing Array [Easy]]. [666: Path Sum IV [Medium]]. [667: Beautiful Arrangement II [Medium]]. [668: Kth Smallest Number in Multiplication Table [Hard]]. [669: Trim a Binary Search Tree [Easy]]. [670: Maximum Swap [Medium]]. [671: Second Minimum Node In a Binary Tree [Easy]]. [672: Bulb Switcher II [Medium]]. [673: Number of Longest Increasing Subsequence [Medium]]. [674: Longest Continuous Increasing Subsequence [Easy]]. [675: Cut Off Trees for Golf Event [Hard]]. [676: Implement Magic Dictionary [Medium]]. [677: Map Sum Pairs [Medium]]. [678: Valid Parenthesis String [Medium]]. [679: 24 Game [Hard]]. [680: Valid Palindrome II [Easy]]. [681: Next Closest Time [Medium]]. [682: Baseball Game [Easy]]. [683: K Empty Slots [Hard]]. [684: Redundant Connection [Medium]]. [685: Redundant Connection II [Hard]]. [686: Repeated String Match [Easy]]. [687: Longest Univalue Path [Easy]]. [688: Knight Probability in Chessboard [Medium]]. [689: Maximum Sum of 3 Non-Overlapping Subarrays [Hard]]. [690: Employee Importance [Easy]]. [691: Stickers to Spell Word [Hard]]. [692: Top K Frequent Words [Medium]]. [693: Binary Number with Alternating Bits [Easy]]. [694: Number of Distinct Islands [Medium]]. [695: Max Area of Island [Medium]]. [696: Count Binary Substrings [Easy]]. [697: Degree of an Array [Easy]]. [698: Partition to K Equal Sum Subsets [Medium]]. [699: Falling Squares [Hard]]. [700: Search in a Binary Search Tree ]]. [Inse701: rt into a Binary Search Tree [Medium]]. [702: Search in a Sorted Array of Unknown Size [Medium]]. [703: Kth Largest Element in a Stream [Easy]]. [704: Binary Search [Easy]]. [705: Design HashSet [Easy]]. [706: Design HashMap [Easy]]. [707: Design Linked List [Medium]]. [708: Insert into a Sorted Circular Linked List [Medium]]. [709: To Lower Case [Easy]]. [710: Random Pick with Blacklist [Hard]]. [711: Number of Distinct Islands II [Hard]]. [712: Minimum ASCII Delete Sum for Two Strings [Medium]]. [713: Subarray Product Less Than K [Medium]]. [714: Best Time to Buy and Sell Stock with Transaction Fee [Medium]]. [715: Range Module [Hard]]. [716: Max Stack [Easy]]. [717: 1-bit and 2-bit Characters [Easy]]. [718: Maximum Length of Repeated Subarray [Medium]]. [719: Find K-th Smallest Pair Distance [Hard]]. [720: Longest Word in Dictionary [Easy]]. [721: Accounts Merge [Medium]]. [722: Remove Comments [Medium]]. [723: Candy Crush [Medium]]. [724: Find Pivot Index [Easy]]. [725: Split Linked List in Parts [Medium]]. [726: Number of Atoms [Hard]]. [727: Minimum Window Subsequence [Hard]]. [728: Self Dividing Numbers [Easy]]. [729: My Calendar I [Medium]]. [730: Count Different Palindromic Subsequences [Hard]]. [731: My Calendar II [Medium]]. [732: My Calendar III [Hard]]. [733: Flood Fill [Easy]]. [734: Sentence Similarity [Easy]]. [735: Asteroid Collision [Medium]]. [736: Parse Lisp Expression [Hard]]. [737: Sentence Similarity II [Medium]]. [738: Monotone Increasing Digits [Medium]]. [739: Daily Temperatures [Medium]]. [740: Delete and Earn [Medium]]. [741: Cherry Pickup [Hard]]. [742: Closest Leaf in a Binary Tree [Medium]]. [743: Network Delay Time [Medium]]. [744: Find Smallest Letter Greater Than Target [Easy]]. [745: Prefix and Suffix Search [Hard]]. [746: Min Cost Climbing Stairs [Easy]]. [747: Largest Number At Least Twice of Others [Easy]]. [748: Shortest Completing Word [Easy]]. [749: Contain Virus [Hard]]. [750: Number Of Corner Rectangles [Medium]]. [751: IP to CIDR [Easy]]. [752: Open the Lock [Medium]]. [753: Cracking the Safe [Hard]]. [754: Reach a Number [Medium]]. [755: Pour Water [Medium]]. [756: Pyramid Transition Matrix [Medium]]. [757: Set Intersection Size At Least Two [Hard]]. [758: Bold Words in String [Easy]]. [759: Employee Free Time [Hard]]. [760: Find Anagram Mappings [Easy]]. [761: Special Binary String [Hard]]. [762: Prime Number of Set Bits in Binary Representation [Easy]]. [763: Partition Labels [Medium]]. [764: Largest Plus Sign [Medium]]. [765: Couples Holding Hands [Hard]]. [766: Toeplitz Matrix [Easy]]. [767: Reorganize String [Medium]]. [768: Max Chunks To Make Sorted II [Hard]]. [769: Max Chunks To Make Sorted [Medium]]. [770: Basic Calculator IV [Hard]]. [771: Jewels and Stones [Easy]]. [772: Basic Calculator III [Hard]]. [773: Sliding Puzzle [Hard]]. [774: Minimize Max Distance to Gas Station [Hard]]. [775: Global and Local Inversions [Medium]]. [776: Split BST [Medium]]. [777: Swap Adjacent in LR String [Medium]]. [778: Swim in Rising Water [Hard]]. [779: K-th Symbol in Grammar [Medium]]. [780: Reaching Points [Hard]]. [781: Rabbits in Forest [Medium]]. [782: Transform to Chessboard [Hard]]. [783: Minimum Distance Between BST Nodes [Easy]]. [784: Letter Case Permutation [Easy]]. [785: Is Graph Bipartite? [Medium]]. [786: K-th Smallest Prime Fraction [Hard]]. [787: Cheapest Flights Within K Stops [Medium]]. [788: Rotated Digits [Easy]]. [789: Escape The Ghosts [Medium]]. [790: Domino and Tromino Tiling [Medium]]. [791: Custom Sort String [Medium]]. [792: Number of Matching Subsequences [Medium]]. [793: Preimage Size of Factorial Zeroes Function [Hard]]. [794: Valid Tic-Tac-Toe State [Medium]]. [795: Number of Subarrays with Bounded Maximum [Medium]]. [796: Rotate String [Easy]]. [797: All Paths From Source to Target [Medium]]. [798: Smallest Rotation with Highest Score [Hard]]. [799: Champagne Tower [Medium]]. [800: Similar RGB Color [Easy]]. [Mini801: mum Swaps To Make Sequences Increasing [Medium]]. [802: Find Eventual Safe States [Medium]]. [803: Bricks Falling When Hit [Hard]]. [804: Unique Morse Code Words [Easy]]. [805: Split Array With Same Average [Hard]]. [806: Number of Lines To Write String [Easy]]. [807: Max Increase to Keep City Skyline [Medium]]. [808: Soup Servings [Medium]]. [809: Expressive Words [Medium]]. [810: Chalkboard XOR Game [Hard]]. [811: Subdomain Visit Count [Easy]]. [812: Largest Triangle Area [Easy]]. [813: Largest Sum of Averages [Medium]]. [814: Binary Tree Pruning [Medium]]. [815: Bus Routes [Hard]]. [816: Ambiguous Coordinates [Medium]]. [817: Linked List Components [Medium]]. [818: Race Car [Hard]]. [819: Most Common Word [Easy]]. [820: Short Encoding of Words [Medium]]. [821: Shortest Distance to a Character [Easy]]. [822: Card Flipping Game [Medium]]. [823: Binary Trees With Factors [Medium]]. [824: Goat Latin [Easy]]. [825: Friends Of Appropriate Ages [Medium]]. [826: Most Profit Assigning Work [Medium]]. [827: Making A Large Island [Hard]]. [828: Unique Letter String [Hard]]. [829: Consecutive Numbers Sum [Hard]]. [830: Positions of Large Groups [Easy]]. [831: Masking Personal Information [Medium]]. [832: Flipping an Image [Easy]]. [833: Find And Replace in String [Medium]]. [834: Sum of Distances in Tree [Hard]]. [835: Image Overlap [Medium]]. [836: Rectangle Overlap [Easy]]. [837: New 21 Game [Medium]]. [838: Push Dominoes [Medium]]. [839: Similar String Groups [Hard]]. [840: Magic Squares In Grid [Easy]]. [841: Keys and Rooms [Medium]]. [842: Split Array into Fibonacci Sequence [Medium]]. [843: Guess the Word [Hard]]. [844: Backspace String Compare [Easy]]. [845: Longest Mountain in Array [Medium]]. [846: Hand of Straights [Medium]]. [847: Shortest Path Visiting All Nodes [Hard]]. [848: Shifting Letters [Medium]]. [849: Maximize Distance to Closest Person [Easy]]. [850: Rectangle Area II [Hard]]. [851: Loud and Rich [Medium]]. [852: Peak Index in a Mountain Array [Easy]]. [853: Car Fleet [Medium]]. [854: K-Similar Strings [Hard]]. [855: Exam Room [Medium]]. [856: Score of Parentheses [Medium]]. [857: Minimum Cost to Hire K Workers [Hard]]. [858: Mirror Reflection [Medium]]. [859: Buddy Strings [Easy]]. [860: Lemonade Change [Easy]]. [861: Score After Flipping Matrix [Medium]]. [862: Shortest Subarray with Sum at Least K [Hard]]. [863: All Nodes Distance K in Binary Tree [Medium]]. [864: Shortest Path to Get All Keys [Hard]]. [865: Smallest Subtree with all the Deepest Nodes [Medium]]. [866: Prime Palindrome [Medium]]. [867: Transpose Matrix [Easy]]. [868: Binary Gap [Easy]]. [869: Reordered Power of 2 [Medium]]. [870: Advantage Shuffle [Medium]]. [871: Minimum Number of Refueling Stops [Hard]]. [872: Leaf-Similar Trees [Easy]]. [873: Length of Longest Fibonacci Subsequence [Medium]]. [874: Walking Robot Simulation [Easy]]. [875: Koko Eating Bananas [Medium]]. [876: Middle of the Linked List [Easy]]. [877: Stone Game [Medium]]. [878: Nth Magical Number [Hard]]. [879: Profitable Schemes [Hard]]. [880: Decoded String at Index [Medium]]. [881: Boats to Save People [Medium]]. [882: Reachable Nodes In Subdivided Graph [Hard]]. [883: Projection Area of 3D Shapes [Easy]]. [884: Uncommon Words from Two Sentences [Easy]]. [885: Spiral Matrix III [Medium]]. [886: Possible Bipartition [Medium]]. [887: Super Egg Drop [Hard]]. [888: Fair Candy Swap [Easy]]. [889: Construct Binary Tree from Preorder and Postorder Traversal [Medium]]. [890: Find and Replace Pattern [Medium]]. [891: Sum of Subsequence Widths [Hard]]. [892: Surface Area of 3D Shapes [Easy]]. [893: Groups of Special-Equivalent Strings [Easy]]. [894: All Possible Full Binary Trees [Medium]]. [895: Maximum Frequency Stack [Hard]]. [896: Monotonic Array [Easy]]. [897: Increasing Order Search Tree [Easy]]. [898: Bitwise ORs of Subarrays [Medium]]. [899: Orderly Queue [Hard]]. [900: RLE Iterator ]]. [901: Online Stock Span [Medium]]. [902: Numbers At Most N Given Digit Set [Hard]]. [903: Valid Permutations for DI Sequence [Hard]]. [904: Fruit Into Baskets [Medium]]. [905: Sort Array By Parity [Easy]]. [906: Super Palindromes [Hard]]. [907: Sum of Subarray Minimums [Medium]]. [908: Smallest Range I [Easy]]. [909: Snakes and Ladders [Medium]]. [910: Smallest Range II [Medium]]. [911: Online Election [Medium]]. [912: Sort an Array [Medium]]. [913: Cat and Mouse [Hard]]. [914: X of a Kind in a Deck of Cards [Easy]]. [915: Partition Array into Disjoint Intervals [Medium]]. [916: Word Subsets [Medium]]. [917: Reverse Only Letters [Easy]]. [918: Maximum Sum Circular Subarray [Medium]]. [919: Complete Binary Tree Inserter [Medium]]. [920: Number of Music Playlists [Hard]]. [921: Minimum Add to Make Parentheses Valid [Medium]]. [922: Sort Array By Parity II [Easy]]. [923: 3Sum With Multiplicity [Medium]]. [924: Minimize Malware Spread [Hard]]. [925: Long Pressed Name [Easy]]. [926: Flip String to Monotone Increasing [Medium]]. [927: Three Equal Parts [Hard]]. [928: Minimize Malware Spread II [Hard]]. [929: Unique Email Addresses [Easy]]. [930: Binary Subarrays With Sum [Medium]]. [931: Minimum Falling Path Sum [Medium]]. [932: Beautiful Array [Medium]]. [933: Number of Recent Calls [Easy]]. [934: Shortest Bridge [Medium]]. [935: Knight Dialer [Medium]]. [936: Stamping The Sequence [Hard]]. [937: Reorder Data in Log Files [Easy]]. [938: Range Sum of BST [Easy]]. [939: Minimum Area Rectangle [Medium]]. [940: Distinct Subsequences II [Hard]]. [941: Valid Mountain Array [Easy]]. [942: DI String Match [Easy]]. [943: Find the Shortest Superstring [Hard]]. [944: Delete Columns to Make Sorted [Easy]]. [945: Minimum Increment to Make Array Unique [Medium]]. [946: Validate Stack Sequences [Medium]]. [947: Most Stones Removed with Same Row or Column [Medium]]. [948: Bag of Tokens [Medium]]. [949: Largest Time for Given Digits [Easy]]. [950: Reveal Cards In Increasing Order [Medium]]. [951: Flip Equivalent Binary Trees [Medium]]. [952: Largest Component Size by Common Factor [Hard]]. [953: Verifying an Alien Dictionary [Easy]]. [954: Array of Doubled Pairs [Medium]]. [955: Delete Columns to Make Sorted II [Medium]]. [956: Tallest Billboard [Hard]]. [957: Prison Cells After N Days [Medium]]. [958: Check Completeness of a Binary Tree [Medium]]. [959: Regions Cut By Slashes [Medium]]. [960: Delete Columns to Make Sorted III [Hard]]. [961: N-Repeated Element in Size 2N Array [Easy]]. [962: Maximum Width Ramp [Medium]]. [963: Minimum Area Rectangle II [Medium]]. [964: Least Operators to Express Number [Hard]]. [965: Univalued Binary Tree [Easy]]. [966: Vowel Spellchecker [Medium]]. [967: Numbers With Same Consecutive Differences [Medium]]. [968: Binary Tree Cameras [Hard]]. [969: Pancake Sorting [Medium]]. [970: Powerful Integers [Easy]]. [971: Flip Binary Tree To Match Preorder Traversal [Medium]]. [972: Equal Rational Numbers [Hard]]. [973: K Closest Points to Origin [Medium]]. [974: Subarray Sums Divisible by K [Medium]]. [975: Odd Even Jump [Hard]]. [976: Largest Perimeter Triangle [Easy]]. [977: Squares of a Sorted Array [Easy]]. [978: Longest Turbulent Subarray [Medium]]. [979: Distribute Coins in Binary Tree [Medium]]. [980: Unique Paths III [Hard]]. [981: Time Based Key-Value Store [Medium]]. [982: Triples with Bitwise AND Equal To Zero [Hard]]. [983: Minimum Cost For Tickets [Medium]]. [984: String Without AAA or BBB [Medium]]. [985: Sum of Even Numbers After Queries [Easy]]. [986: Interval List Intersections [Medium]]. [987: Vertical Order Traversal of a Binary Tree [Medium]]. [988: Smallest String Starting From Leaf [Medium]]. [989: Add to Array-Form of Integer [Easy]]. [990: Satisfiability of Equality Equations [Medium]]. [991: Broken Calculator [Medium]]. [992: Subarrays with K Different Integers [Hard]]. [993: Cousins in Binary Tree [Easy]]. [994: Rotting Oranges [Easy]]. [995: Minimum Number of K Consecutive Bit Flips [Hard]]. [996: Number of Squareful Arrays [Hard]]. [997: Find the Town Judge [Easy]]. [998: Maximum Binary Tree II [Medium]]. [999: Available Captures for Rook [Easy]]. [1000: Minimum Cost to Merge Stones [Hard]]. [1002: Find Common Characters [Easy]]. [1003: Check If Word Is Valid After Substitutions [Medium]]. [1004: Max Consecutive Ones III [Medium]]. [1005: Maximize Sum Of Array After K Negations [Easy]]. [1006: Clumsy Factorial [Medium]]. [1007: Minimum Domino Rotations For Equal Row [Medium]]. [1008: Construct Binary Search Tree from Preorder Traversal [Medium]]. [1009: Complement of Base 10 Integer [Easy]]. [1010: Pairs of Songs With Total Durations Divisible by 60 [Easy]]. [1011: Capacity To Ship Packages Within D Days [Medium]]. [1012: Numbers With Repeated Digits [Hard]]. [1013: Partition Array Into Three Parts With Equal Sum [Easy]]. [1014: Best Sightseeing Pair [Medium]]. [1015: Smallest Integer Divisible by K [Medium]]. [1016: Binary String With Substrings Representing 1 To N [Medium]]. [1017: Convert to Base -2 [Medium]]. [1018: Binary Prefix Divisible By 5 [Easy]]. [1019: Next Greater Node In Linked List [Medium]]. [1020: Number of Enclaves [Medium]]. [1021: Remove Outermost Parentheses [Easy]]. [1022: Sum of Root To Leaf Binary Numbers [Easy]]. [1023: Camelcase Matching [Medium]]. [1024: Video Stitching [Medium]]. [1025: Divisor Game [Easy]]. [1026: Maximum Difference Between Node and Ancestor [Medium]]. [1027: Longest Arithmetic Sequence [Medium]]. [1028: Recover a Tree From Preorder Traversal [Hard]]. [1029: Two City Scheduling [Easy]]. [1030: Matrix Cells in Distance Order [Easy]]. [1031: Maximum Sum of Two Non-Overlapping Subarrays [Medium]]. [1032: Stream of Characters [Hard]]. [1033: Moving Stones Until Consecutive [Easy]]. [1034: Coloring A Border [Medium]]. [1035: Uncrossed Lines [Medium]]. [1036: Escape a Large Maze [Hard]]. [1037: Valid Boomerang [Easy]]. [1038: Binary Search Tree to Greater Sum Tree [Medium]]. [1039: Minimum Score Triangulation of Polygon [Medium]]. [1040: Moving Stones Until Consecutive II [Medium]]. [1041: Robot Bounded In Circle [Medium]]. [1042: Flower Planting With No Adjacent [Easy]]. [1043: Partition Array for Maximum Sum [Medium]]. [1044: Longest Duplicate Substring [Hard]]. [1045: Customers Who Bought All Products [Medium]]. [1046: Last Stone Weight [Easy]]. [1047: Remove All Adjacent Duplicates In String [Easy]]. [1048: Longest String Chain [Medium]]. [1049: Last Stone Weight II [Medium]]. [1050: Actors and Directors Who Cooperated At Least Three Times [Easy]]. [1051: Height Checker [Easy]]. [1052: Grumpy Bookstore Owner [Medium]]. [1053: Previous Permutation With One Swap [Medium]]. [1054: Distant Barcodes [Medium]]. [1055: Shortest Way to Form String [Medium]]. [1056: Confusing Number [Easy]]. [1057: Campus Bikes [Medium]]. [1058: Minimize Rounding Error to Meet Target [Medium]]. [1059: All Paths from Source Lead to Destination [Medium]]. [1060: Missing Element in Sorted Array [Medium]]. [1061: Lexicographically Smallest Equivalent String [Medium]]. [1062: Longest Repeating Substring [Medium]]. [1063: Number of Valid Subarrays [Hard]]. [1064: Fixed Point [Easy]]. [1065: Index Pairs of a String [Easy]]. [1066: Campus Bikes II [Medium]]. [1067: Digit Count in Range [Hard]]. [1068: Product Sales Analysis I [Easy]]. [1069: Product Sales Analysis II [Easy]]. [1070: Product Sales Analysis III [Medium]]. [1071: Greatest Common Divisor of Strings [Easy]]. [1072: Flip Columns For Maximum Number of Equal Rows [Medium]]. [1073: Adding Two Negabinary Numbers [Medium]]. [1074: Number of Submatrices That Sum to Target [Hard]]. [1075: Project Employees I [Easy]]. [1076: Project Employees II [Easy]]. [1077: Project Employees III [Medium]]. [1078: Occurrences After Bigram [Easy]]. [1079: Letter Tile Possibilities [Medium]]. [1080: Insufficient Nodes in Root to Leaf Paths [Medium]]. [1081: Smallest Subsequence of Distinct Characters [Medium]]. [1082: Sales Analysis I [Easy]]. [1083: Sales Analysis II [Easy]]. [1084: Sales Analysis III [Easy]]. [1085: Sum of Digits in the Minimum Number [Easy]]. [1086: High Five [Easy]]. [1087: Brace Expansion [Medium]]. [1088: Confusing Number II [Hard]]. [1089: Duplicate Zeros [Easy]]. [1090: Largest Values From Labels [Medium]]. [1091: Shortest Path in Binary Matrix [Medium]]. [1092: Shortest Common Supersequence [Hard]]. [1093: Statistics from a Large Sample [Medium]]. [1094: Car Pooling [Medium]]. [1095: Find in Mountain Array [Hard]]. [1096: Brace Expansion II [Hard]]. [1097: Game Play Analysis V [Hard]]. [1098: Unpopular Books [Medium]]. [1099: Two Sum Less Than K [Easy]]. [1100: Find K-Length Substrings With No Repeated Characters [Medium]]. [The 1101: Earliest Moment When Everyone Become Friends [Medium]]. [1102: Path With Maximum Minimum Value [Medium]]. [1103: Distribute Candies to People [Easy]]. [1104: Path In Zigzag Labelled Binary Tree [Medium]]. [1105: Filling Bookcase Shelves [Medium]]. [1106: Parsing A Boolean Expression [Hard]]. [1107: New Users Daily Count [Medium]]. [1108: Defanging an IP Address [Easy]]. [1109: Corporate Flight Bookings [Medium]]. [1110: Delete Nodes And Return Forest [Medium]]. [1111: Maximum Nesting Depth of Two Valid Parentheses Strings [Medium]]. [1112: Highest Grade For Each Student [Medium]]. [1113: Reported Posts [Easy]]. [1114: Print in Order [Easy]]. [1115: Print FooBar Alternately [Medium]]. [1116: Print Zero Even Odd [Medium]]. [1117: Building H2O [Medium]]. [1118: Number of Days in a Month [Easy]]. [1119: Remove Vowels from a String [Easy]]. [1120: Maximum Average Subtree [Medium]]. [1121: Divide Array Into Increasing Sequences [Hard]]. [1122: Relative Sort Array [Easy]]. [1123: Lowest Common Ancestor of Deepest Leaves [Medium]]. [1124: Longest Well-Performing Interval [Medium]]. [1125: Smallest Sufficient Team [Hard]]. [1126: Active Businesses [Medium]]. [1127: User Purchase Platform [Hard]]. [1128: Number of Equivalent Domino Pairs [Easy]]. [1129: Shortest Path with Alternating Colors [Medium]]. [1130: Minimum Cost Tree From Leaf Values [Medium]]. [1131: Maximum of Absolute Value Expression [Medium]]. [1132: Reported Posts II [Medium]]. [1133: Largest Unique Number [Easy]]. [1134: Armstrong Number [Easy]]. [1135: Connecting Cities With Minimum Cost [Medium]]. [1136: Parallel Courses [Hard]]. [1137: N-th Tribonacci Number [Easy]]. [1138: Alphabet Board Path [Medium]]. [1139: Largest 1-Bordered Square [Medium]]. [1140: Stone Game II [Medium]]. [1141: User Activity for the Past 30 Days I [Easy]]. [1142: User Activity for the Past 30 Days II [Easy]]. [1143: Longest Common Subsequence [Medium]]. [1144: Decrease Elements To Make Array Zigzag [Medium]]. [1145: Binary Tree Coloring Game [Medium]]. [1146: Snapshot Array [Medium]]. [1147: Longest Chunked Palindrome Decomposition [Hard]]. [1148: Article Views I [Easy]]. [1149: Article Views II [Medium]]. [1150: Check If a Number Is Majority Element in a Sorted Array [Easy]]. [1151: Minimum Swaps to Group All 1's Together [Medium]]. [1152: Analyze User Website Visit Pattern [Medium]]. [1153: String Transforms Into Another String [Hard]]. [1154: Day of the Year [Easy]]. [1155: Number of Dice Rolls With Target Sum [Medium]]. [1156: Swap For Longest Repeated Character Substring [Medium]]. [1157: Online Majority Element In Subarray [Hard]]. [1158: Market Analysis I [Medium]]. [1159: Market Analysis II [Hard]]. [1160: Find Words That Can Be Formed by Characters [Easy]]. [1161: Maximum Level Sum of a Binary Tree [Medium]]. [1162: As Far from Land as Possible [Medium]]. [1163: Last Substring in Lexicographical Order [Hard]]. [1164: Product Price at a Given Date [Medium]]. [1165: Single-Row Keyboard [Easy]]. [1166: Design File System [Medium]]. [1167: Minimum Cost to Connect Sticks [Medium]]. [1168: Optimize Water Distribution in a Village [Hard]]. [1169: Invalid Transactions [Medium]]. [1170: Compare Strings by Frequency of the Smallest Character [Easy]]. [1171: Remove Zero Sum Consecutive Nodes from Linked List [Medium]]. [1172: Dinner Plate Stacks [Hard]]. [1173: Immediate Food Delivery I [Easy]]. [1174: Immediate Food Delivery II [Medium]]. [1175: Prime Arrangements [Easy]]. [1176: Diet Plan Performance [Easy]]. [1177: Can Make Palindrome from Substring [Medium]]. [1178: Number of Valid Words for Each Puzzle [Hard]]. [1179: Reformat Department Table [Easy]]. [1180: Count Substrings with Only One Distinct Letter [Easy]]. [1181: Before and After Puzzle [Medium]]. [1182: Shortest Distance to Target Color [Medium]]. [1183: Maximum Number of Ones [Hard]]. [1184: Distance Between Bus Stops [Easy]]. [1185: Day of the Week [Easy]]. [1186: Maximum Subarray Sum with One Deletion [Medium]]. [1187: Make Array Strictly Increasing [Hard]]. [1188: Design Bounded Blocking Queue [Medium]]. [1189: Maximum Number of Balloons [Easy]]. [1190: Reverse Substrings Between Each Pair of Parentheses [Medium]]. [1191: K-Concatenation Maximum Sum [Medium]]. [1192: Critical Connections in a Network [Hard]]. [1193: Monthly Transactions I [Medium]]. [1194: Tournament Winners [Hard]]. [1195: Fizz Buzz Multithreaded [Medium]]. [1196: How Many Apples Can You Put into the Basket [Easy]]. [1197: Minimum Knight Moves [Medium]]. [1198: Find Smallest Common Element in All Rows [Medium]]. [1199: Minimum Time to Build Blocks [Hard]]. [1200: Minimum Absolute Difference [Easy]]. [1201: Ugly Number III [Medium]]. [1202: Smallest String With Swaps [Medium]]. [1203: Sort Items by Groups Respecting Dependencies [Hard]]. [1204: Last Person to Fit in the Elevator [Medium]]. [1205: Monthly Transactions II [Medium]]. [1206: Design Skiplist [Hard]]. [1207: Unique Number of Occurrences [Easy]]. [1208: Get Equal Substrings Within Budget [Medium]]. [1209: Remove All Adjacent Duplicates in String II [Medium]]. [1210: Minimum Moves to Reach Target with Rotations [Hard]]. [1211: Queries Quality and Percentage [Easy]]. [1212: Team Scores in Football Tournament [Medium]]. [1213: Intersection of Three Sorted Arrays [Easy]]. [1214: Two Sum BSTs [Medium]]. [1215: Stepping Numbers [Medium]]. [1216: Valid Palindrome III [Hard]]. [1217: Play with Chips [Easy]]. [1218: Longest Arithmetic Subsequence of Given Difference [Medium]]. [1219: Path with Maximum Gold [Medium]]. [1220: Count Vowels Permutation [Hard]]. [1221: Split a String in Balanced Strings [Easy]]. [1222: Queens That Can Attack the King [Medium]]. [1223: Dice Roll Simulation [Medium]]. [1224: Maximum Equal Frequency [Hard]]. [1225: Report Contiguous Dates [Hard]]. [1226: The Dining Philosophers [Medium]]. [1227: Airplane Seat Assignment Probability [Medium]]. [1228: Missing Number In Arithmetic Progression [Easy]]. [1229: Meeting Scheduler [Medium]]. [1230: Toss Strange Coins [Medium]]. [1231: Divide Chocolate [Hard]]. [1232: Check If It Is a Straight Line [Easy]]. [1233: Remove Sub-Folders from the Filesystem [Medium]]. [1234: Replace the Substring for Balanced String [Medium]]. [1235: Maximum Profit in Job Scheduling [Hard]]. [1236: Web Crawler [Medium]]. [1237: Find Positive Integer Solution for a Given Equation [Easy]]. [1238: Circular Permutation in Binary Representation [Medium]]. [1239: Maximum Length of a Concatenated String with Unique Characters [Medium]]. [1240: Tiling a Rectangle with the Fewest Squares [Hard]]. [1241: Number of Comments per Post [Easy]]. [1242: Web Crawler Multithreaded [Medium]]. [1243: Array Transformation [Easy]]. [1244: Design A Leaderboard [Medium]]. [1245: Tree Diameter [Medium]]. [1246: Palindrome Removal [Hard]]. [1247: Minimum Swaps to Make Strings Equal [Medium]]. [1248: Count Number of Nice Subarrays [Medium]]. [1249: Minimum Remove to Make Valid Parentheses [Medium]]. [1250: Check If It Is a Good Array [Hard]]. [1251: Average Selling Price [Easy]]. [1252: Cells with Odd Values in a Matrix [Easy]]. [1253: Reconstruct a 2-Row Binary Matrix [Medium]]. [1254: Number of Closed Islands [Medium]]. [1255: Maximum Score Words Formed by Letters [Hard]]. [1256: Encode Number [Medium]]. [1257: Smallest Common Region [Medium]]. [1258: Synonymous Sentences [Medium]]. [1259: Handshakes That Don't Cross [Hard]]. [1260: Shift 2D Grid [Easy]]. [1261: Find Elements in a Contaminated Binary Tree [Medium]]. [1262: Greatest Sum Divisible by Three [Medium]]. [1263: Minimum Moves to Move a Box to Their Target Location [Hard]]. [1264: Page Recommendations [Medium]]. [1265: Print Immutable Linked List in Reverse [Medium]]. [1266: Minimum Time Visiting All Points [Easy]]. [1267: Count Servers that Communicate [Medium]]. [1268: Search Suggestions System [Medium]]. [1269: Number of Ways to Stay in the Same Place After Some Steps [Hard]]. [1270: All People Report to the Given Manager [Medium]]. [1272: Remove Interval [Medium]]. [1273: Delete Tree Nodes [Medium]]. [1274: Number of Ships in a Rectangle [Hard]]. [1275: Find Winner on a Tic Tac Toe Game [Easy]]. [1276: Number of Burgers with No Waste of Ingredients [Medium]]. [1277: Count Square Submatrices with All Ones [Medium]]. [1278: Palindrome Partitioning III [Hard]]. [1279: Traffic Light Controlled Intersection [Easy]]. [1280: Students and Examinations [Easy]]. [1281: Subtract the Product and Sum of Digits of an Integer [Easy]]. [1282: Group the People Given the Group Size They Belong To [Medium]]. [1283: Find the Smallest Divisor Given a Threshold [Medium]]. [1284: Minimum Number of Flips to Convert Binary Matrix to Zero Matrix [Hard]]. [1285: Find the Start and End Number of Continuous Ranges [Medium]]. [1286: Iterator for Combination [Medium]]. [1287: Element Appearing More Than 25% In Sorted Array [Easy]]. [1288: Remove Covered Intervals [Medium]]. [1289: Minimum Falling Path Sum II [Hard]]. [1290: Convert Binary Number in a Linked List to Integer [Easy]]. [1291: Sequential Digits [Medium]]. [1292: Maximum Side Length of a Square with Sum Less than or Equal to Threshold [Medium]]. [1293: Shortest Path in a Grid with Obstacles Elimination [Hard]]. [1294: Weather Type in Each Country [Easy]]. [1295: Find Numbers with Even Number of Digits [Easy]]. [1296: Divide Array in Sets of K Consecutive Numbers [Medium]]. [1297: Maximum Number of Occurrences of a Substring [Medium]]. [1298: Maximum Candies You Can Get from Boxes [Hard]]. [1299: Replace Elements with Greatest Element on Right Side [Easy]]. [1300: Sum of Mutated Array Closest to Target [Medium]]. [1301: Number of Paths with Max Score [Hard]]. [1302: Deepest Leaves Sum [Medium]]. [1303: Find the Team Size [Easy]]. [1304: Find N Unique Integers Sum up to Zero [Easy]]. [1305: All Elements in Two Binary Search Trees [Medium]]. [1306: Jump Game III [Medium]]. [1307: Verbal Arithmetic Puzzle [Hard]]. [1308: Running Total for Different Genders [Medium]]. [1309: Decrypt String from Alphabet to Integer Mapping [Easy]]. [1310: XOR Queries of a Subarray [Medium]]. [1311: Get Watched Videos by Your Friends [Medium]]. [1312: Minimum Insertion Steps to Make a String Palindrome [Hard]].