JavaScript-Algorithms | JS算法 数据结构 精华集 | Learning library
kandi X-RAY | JavaScript-Algorithms Summary
kandi X-RAY | JavaScript-Algorithms Summary
JavaScript-Algorithms
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
- Add two numbers .
- Sorting array sort
- Sorts array sort .
- compares two sequence strings
- Bubble array sort .
- Insert an element into the list .
- shallow shuffle .
- binary sort function
- Adds leading zeros to the given string .
JavaScript-Algorithms Key Features
JavaScript-Algorithms Examples and Code Snippets
function matrixChainOrder(p) {
const n = p.length;
const m = [];
const s = [];
for (let i = 1; i <= n; i++) {
m[i] = [];
m[i][i] = 0;
}
for (let i = 0; i <= n; i++) {
// to help printing the optimal solution
s[i] = [
function countingSort(array) {
if (array.length < 2) {
return array;
}
const maxValue = findMaxValue(array);
let sortedIndex = 0;
const counts = new Array(maxValue + 1);
array.forEach(element => {
if (!counts[element]) {
function binarySearch(array, value, compareFn = defaultCompare) {
const sortedArray = quickSort(array);
let low = 0;
let high = sortedArray.length - 1;
while (low <= high) {
const mid = Math.floor((low + high) / 2);
const element =
Community Discussions
Trending Discussions on JavaScript-Algorithms
QUESTION
Say you have a bunch of actions for creating/inserting records into a bunch of different database tables. You have some records which can be inserted without any dependency on the output of any other insert. You have some which need to wait for one other thing to finish. And you have others that need to wait for many things to finish, which might finish at different times in the flow.
How can you write an algorithm which would sort and chunk the actions in the dependency tree so the inserts / database actions can be optimally batched? By optimally batched, I mean if you can insert 10 records into the same table at once, then do that. Any time you can batch insert, you should, to minimize the number of database calls/inserts.
Here is a snippet from the example code I whipped together with a fake sequence of actions using a simple data structure to capture all the required information.
...ANSWER
Answered 2022-Jan-19 at 05:50Your data structure isn't clear to me. What are the single letter ids p
, q
, etc.? I also don't understand the role of tables. You can insert multiple items in the same table in one write, no? I'm assuming these tihngs don't matter in the root sequencing problem.
I'm treating the set
field as a "job" and the corresponding keys mentioned in the inputs
as dependencies: jobs that must be completed before it.
I don't have time to be thorough here, and I don't have a javascript environment handy, so this is in Python.
Let's extract a dependency graph from the the verbose data structure. Then look for "levels." The first level is all nodes with no dependencies. The second is all nodes with dependencies met in any previous level, etc. Rinse and repeate.
Note unlike I was thinking in my note in comments, this is not a level graph by the traditional definition.
Also, I'm not going to bother with data structures to make this efficient. You could do it in O(n log n) time. My code is O(n^2).
Sorry if I'm misinterpreting your question. Also sorry for untested, possibly buggy implementation here.
QUESTION
To my understanding, if the loop variable of a for loop is defined with var, then any change on that variable is applied globally. for example:
...ANSWER
Answered 2022-Jan-19 at 11:17however, the above code prints 3. What is the reason for this?
Because you assign 3
to the i
variable that printNumTwo
closes over. It doesn't matter that the assignment happens after printNumTwo
is created, only that it is the variable that printNumTwo
is using.
The difference between var
and let
in for
loops is that a new variable is created for the body of the loop on each loop iteration with let
. But you're assigning to that variable within the loop body, so the function closing over (printNumTwo
) it sees that value later when you call it.
It's exactly like this:
QUESTION
I was trying to do the following challenge from freecodecamp: https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/wherefore-art-thou and I have a couple questions about it.
- Why is my attempt working in my local console but not on freecodecamp? Meaning, out of all the tests, 3 out of 4 are correct in my console, but none of them is on FCC.
- Why is this test
whatIsInAName([{ "apple": 1, "bat": 2 }, { "bat": 2 }, { "apple": 1, "bat": 2, "cookie": 2 }], { "apple": 1, "bat": 2 })
not passing if all the others are?
My attempt with expected results:
...ANSWER
Answered 2022-Jan-09 at 20:19- Using
Object#entries
, get the list of key-value pairs fromsource
- Using
Array#filter
, iterate overcollection
. In every iteration, usingArray#every
, check if all entries in the abovesourceEntries
match the current object
QUESTION
I am studying now at FreeCodeCamp, and here is a challenge:
"We have defined a function, copyMachine which takes arr (an array) and num (a number) as arguments. The function is supposed to return a new array made up of num copies of arr. We have done most of the work for you, but it doesn't work quite right yet. Modify the function using spread syntax so that it works correctly (hint: another method we have already covered might come in handy here!)."
And here is a solution:
...ANSWER
Answered 2021-Sep-02 at 16:00It's the matter of reference.
When using this syntax newArr.push(arr)
, you're pushing the original array from the argument, so whenever the arr
changes its content, arrays inside newArr will also update since it is always the same one array.
When using spread syntax, you're actually pushing a copy of that arr
. This mean it's a new array that is not tied to the array you pass to a function
Consider this
QUESTION
function checkRange(num, temp) {
for (var i = 1; i < num; i++) {
console.log(temp % i, i, temp);
if (temp % i != 0) {
return false;
}
}
return true;
}
function smallestCommons(arr) {
arr.sort((a, b) => {return a > b})
var two = [arr[1]];
var check = false;
while (check == false) {
two.push(two[two.length - 1] + arr[1])
if (checkRange(arr[1], two[two.length - 1]) == true) {
check = true;
return two[two.length - 1];
}
}
console.log(two);
// not sure what to do with this
return two[two.length - 1];
}
smallestCommons([1, 13]);
...ANSWER
Answered 2021-Jul-18 at 17:32This was my answer when I was learning:
QUESTION
I'm learning a bit of JavaScript, but I'm having hard time understanding the lesson on FreeCodeCamp about the recursion countdown (link).
In the lesson, there this initial example. But I'm confused on how it operates:
...ANSWER
Answered 2021-Jun-01 at 17:26Here what the array looks like inside of each function call if this helps:
QUESTION
I am trying to complete the "Map the Debris" freecodecamp challenge https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/map-the-debris, and I think I've gotten it. It works from my PC's code editor, but when I copy/paste into the website area the conditions don't satisfy.
How do I best debug this?
My code is
...ANSWER
Answered 2021-Feb-05 at 02:40You have to parse to int the orbSec variable
Just replace this line:
QUESTION
This is a follow up to my questions on the Arguments Optional Challenge in Freecodecamp (see below0:
I have now satisfied 5/6 conditions of the challenge, except for when the input is addTogether(2,([3])), which returns '23' as a string instead of the correct 'undefined'.
If the [3] is an array, and an array is an object, shouldn't my checkNum function work to label that as undefined? Where was the string generated?
my code now:
...ANSWER
Answered 2021-Feb-04 at 05:28We can declare functions in 2 ways, the regular way:
QUESTION
Hello guys I am having some issues understanding this challenge from FreeCodeCamp< i just did all the steps that I was told to do on the challange but I can just get it to work, here is the link
And here is my solution
...ANSWER
Answered 2020-Dec-15 at 19:13I am sharing my solution which is slightly different from yours. Compare it to your own. You will see that I only return inside my for loop when I get a positive match , otherwise I let the loop run. This is the biggest difference. You need to let the loop run fully and then through some mechanism keep track of the missing conditions . I have used two different variables to track the missing conditions here.
QUESTION
This regex has to match passwords that are greater than 5 characters long, do not begin with numbers, and have two consecutive digits.
All the test cases are passing the regex test.
My regex is /(?=^[a-z]+\d{2,})(?=\w{5,})/
I have to use two positive lookaheads to solve this problem to pass the tests.
But astr1on11aut is not passing the test. Why?
Link to problem- https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/regular-expressions/positive-and-negative-lookahead
...ANSWER
Answered 2020-Nov-10 at 07:25If you are not limited to using a single regex, I suggest splitting this into multiple tests in your host language (e.g. JavaScript):
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install JavaScript-Algorithms
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page