Divisible Sum Pairs, Non Divisible Subset Hacker Rank Solution in C

https://www.hackerrank.com/challenges/divisible-sum-pairs/problem

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int main() {
    int n,result=0;
    int k,j;
    scanf("%i %i", &n, &k);
    int *ar = malloc(sizeof(int) * n);
    for(int ar_i = 0; ar_i < n; ar_i++){
       scanf("%i",&ar[ar_i]);
    }
    for(int ar_i = 0; ar_i < n-1; ar_i++){
      for(j=ar_i+1;j<n;j++)
          if((ar[ar_i]+ar[j])%k == 0)
              result++;
    }
    printf("%d\n", result);
    return 0;
}

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https://www.hackerrank.com/challenges/non-divisible-subset/problem


#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
int max(int a,int b)
{
    if(a>b)
        return a;
    return b;
}

int nonDivisibleSubset(int k, int arr_size, int* arr) {
    // Complete this function
    int h[101]={0},result=0,i,j;
    for(i=0;i<arr_size;i++)
        h[(arr[i]%k)]++;
    if(h[0] != 0) result++;
    for(i=1,j=k-1;i<j;i++,j--)
    {
        result=result+max(h[i],h[j]);
    }
    if(k%2 == 0 && h[k/2] != 0)
        result++;
    return result;
}

int main() {
    int n;
    int k;
    scanf("%i %i", &n, &k);
    int *arr = malloc(sizeof(int) * n);
    for (int arr_i = 0; arr_i < n; arr_i++) {
       scanf("%i",&arr[arr_i]);
    }
    int result = nonDivisibleSubset(k, n, arr);
    printf("%d\n", result);
    return 0;
}