Hackerearth | Solutions to problems on Hackerearth | Learning library

I am working on to improve my coding skill.
So I joined hackerearth to solve coding problems in PHP language because I know PHP.
But on the very first question I got stuck because I don't know how to take input as an array of size N.

The problem on which I am stuck is given below -
Coding challenge -
Monk loves to preform different operations on arrays, and so being the principal of Hackerearth School, he assigned a task to his new student Mishki. Mishki will be provided with an integer array A of size N and an integer K , where she needs to rotate the array in the right direction by K steps and then print the resultant array. As she is new to the school, please help her to complete the task.

What I have tried to solve the problem-
As this problem ask for 3 inputs - First the number of test cases (T).
Second is the size of the array (N) and number of rotation (K).
Third array of size N.
So I have successfully passed the first test case (code is given below)-

PROBLEM STATEMENT :

Find maximum difference between the prime numbers in the given range. [L,R]

SOME CONDITION EXAMPLE :

Range: [ 1, 10 ] The maximum difference between the prime numbers in the given range is 5.

Difference = 7 - 2 = 5

Range: [ 5, 5 ] There is only one distinct prime number so the maximum difference would be 0.

Range: [ 8 , 10 ] There is no prime number in the given range so the output for the given range would be -1.

Range: [ 2 - 7 ] . This should return 5. [ 7 - 2 ] = 5

R Code :

The below R code works fine in R studio for all input I have passed. But when I ran the similar code in hackerEarth Env. Getting Errors

I will have an interview with a company which like the hackerearth.com. I don't know how to work and doing the code perfectly. Could you help me with the following example? This is the example for the .hackerearth.com, however, I don't know that I should consider the constraint in the code? can I use a package like NumPy? or I should only use the basic calculation with my self? Could you check my response and let me know the problem with that? Thank you so much

Input Format:

First line of input consists of an integer N denoting the number of elements in the array A. Second line consists of N space separated integers denoting the array elements.

Output Format:

The only line of output consists of the value of x.

Input Constraints: 1<100

1<100

explanation:

An initial sum of array is 1+2+3+4+5=15 When we update all elements to 4, the sum of array which is greater than 15 . Note that if we had updated the array elements to 3, which is not greater than 15 . So, 4 is the minimum value to which array elements need to be updated.

I was trying to solve the problem Modulo strength at hackerearth ,
https://www.hackerearth.com/practice/basic-programming/implementation/basics-of-implementation/practice-problems/golf/modulo-strength-4/ ,
so basically we have to find all such pairs of no. (say i,j) such that A[i]%k=A[j]%k where k is a no. given in the question ,
i tried brute force approach and got time limit exceeded at some of the last test cases and
in the discussion tab i found a code which is working but i couldn't understand what exactly it does, and the underlying thinking behind the algorithm used.

I am trying to solve the Minimum AND xor OR problem (here) from the hacker rank, it runs well in the sample case but in the 1st input case scenario where the number of test case(T) is 1000 it provides 20 wrong answers
Ex.: The input array of 10 numbers [853, 864, 10, 547, 954, 235, 822, 429, 628, 569] gives the result 53 while the correct ans is 26. (rest 980 are correct), and in rest of the input case scenario the time limits exceeds. I tried to debug but am hitting the dead-end.
Is there any way to make it more feasible, apart from using different sorting method(like qsort) ?

Recently, I encountered a problem on the HackerEarth platform, the main idea for solving the problem was to find which suffixes of a string are also the same string's prefix in linear time(in size of string). For example, in string "abcdzyabc", "abc" is a suffix of the string and it is also its prefix. We need to find all such suffixes in linear time.

Now say I have a boolean array, isSuffixPrefix? of size n i.e. the length of the string str. isSuffixPrefix?[i] is true if the suffix of string str starting at index i i.e. suffix str[i...n-1] is also a prefix of the same string str, it is false otherwise. How can we compute this array in linear time (if possible)?

An example for string s = "aaa":

I have been asked one question in the HackerEarth coding platform, to find pairs x and y from the arrays that satisfy the above equation.

Why is break used here to break out of if statement? Is it allowed?

And why are x and y made 0 at the end? x = 0; y = 0

https://www.hackerearth.com/practice/basic-programming/input-output/basics-of-input-output/practice-problems/algorithm/vowels-love/submissions/**

Dijkstra time complexity is O(V+ElogV) with binary heaps.

But, C++ pq(if used as binary heap), does not support decrease key. One solution suggested is to just insert the same vertex again in pq with decreased distance. For, ex:

From: https://www.hackerearth.com/practice/algorithms/graphs/shortest-path-algorithms/tutorial/