全部WA，样例过

#include <bits/stdc++.h>
using namespace std;
struct bag {
	int m, v;
	double sum;
} a[110];
bool cmp(bag x, bag y) {
	if (x.sum > y.sum) {
		return 1;
	}
	return 0;
}
int main() {
	int n, t;
	cin >> n >> t;
	int heavy;
	double money;
	for (int i = 1; i <= n; i++) {
		cin >> a[i].m >> a[i].v;
		a[i].sum = a[i].v / a[i].m;
	}
	sort(a + 1, a + n + 1, cmp);
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= a[i].m; j++) {
			if (heavy >= t) {
				break;
			}
			money += a[i].sum;
			heavy++;
		}
		if (heavy >= t) {
			break;
		}
	}
	printf("%.2f", money);
	return 0;
}

求助！！！