[伯俊/BOJ]12788第2回IUPCは順調に開催できますか?[Silver 4]

#include <stdio.h>
void QuickSort(int* arr, int start, int end)
{
	if (start >= end)
		return;
	int piv = start, left = start + 1, right = end, temp;
	while (left < right)
	{
		while (left <= end && arr[left] >= arr[piv])
			left++;
		while (right > start && arr[right] <= arr[piv])
			right--;
		if (left > right)
		{
			temp = arr[right];
			arr[right] = arr[piv];
			arr[piv] = temp;
		}
		else
		{
			temp = arr[right];
			arr[right] = arr[left];
			arr[left] = temp;
		}
	}
	QuickSort(arr, start, right - 1);
	QuickSort(arr, right + 1, end);
}
int main()
{
	int N, M, K, A[1000] = { 0 }, cnt = 0, sum = 0;
	scanf("%d", &N);
	scanf("%d %d", &M, &K);
	for (int i = 0; i < N; i++)
		scanf("%d", &A[i]);
	int people = M * K;
	QuickSort(A, 0, N - 1);
	for (int i = 0; i < N; i++)
	{
		if (sum < people)
		{
			sum += A[i];
			cnt++;
		}
		else
			break;
	}
	if (sum >= people)
		printf("%d", cnt);
	else
		printf("STRESS");
	return 0;
}