P2676 [USACO07DEC] Bookshelf B RE了三个 求调

#include<bits/stdc++.h>
using namespace std;
int n,b,a[1000001],ans;
long long sum;
bool cmp(int x1,int x2)
{
	if (x1>=x2)
	return 1;
	else 
	return 0;
}
int main()
{
	cin>>n>>b;
	for (int i=1;i<=n;i++)
	{
		cin>>a[i];
	}
	sort(a+1,a+n+1,cmp);
	for (int i=1;i<=n;i++)
	{
		sum=sum+a[i];
		ans++;
		if (sum>b)
		break;
	}
	cout<<ans;
	return 0;
}