Need Help in Google Kick Start Round A - Houses Problem

help
1

Here is the link to theQuestion.

#include<stdio.h>

void swap(int* a, int* b);
int partition (int arr[], int low, int high);
void quickSort(int arr[], int low, int high);

int main()
{
    int t;
    scanf("%d",&t);
    for(int j=0;j<t;j++){
        int n,b;
        scanf("%d %d",&n,&b);
        int arr[n];
        for(int i=0;i<n;i++)
            scanf("%d",&arr[i]);
        quickSort(arr,0,n-1);
        int count=0;
        for(int i=0;b>0;i++){
            if(i==n-1)
              break;
            b-=arr[i];
            if(b>=0)
              count++;
        }
        printf("Case #%d: %d\n",j+1,count);

    }
}

void swap(int* a, int* b)
{
    int t = *a;
    *a = *b;
    *b = t;
}


int partition (int arr[], int low, int high)
{
    int pivot = arr[high];
    int i = (low - 1);

    for (int j = low; j <= high- 1; j++)
    {

        if (arr[j] < pivot)
        {
            i++;
            swap(&arr[i], &arr[j]);
        }
    }
    swap(&arr[i + 1], &arr[high]);
    return (i + 1);
}


void quickSort(int arr[], int low, int high)
{
    if (low < high)
    {

        int pi = partition(arr, low, high);


        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}

It is displaying Wrong Answer for this code. The code is working fine for the test cases. So where is the code failing?

2

You should break when i equals n because else you would never be able to include the (n-1)th element.

3

We have a inbuilt optimised sort. Just write
sort(arr,arr+n);