题解

按照题意模拟一遍就行了，用不到任何算法

ac code

#include<bits/stdc++.h>
typedef long long LL;
using namespace std;
const int N = 1e5 + 10;
int summ,t,n;
int main ()
{
	cin >> t; 
	for(int i = 1;i <= t;++ i)
	{
		int tmp;
		cin >> tmp;
		n += 500 - tmp;
		if(n < 0){
			cout << 0 - i << "\n";
			return 0;
		}
		if(n >= 100){
			int tmp1 = n/100;
			n -= 100 * tmp1;
			summ += tmp1 * 100;
		}
	}
	cout << 1.2 * summ + n << "\n";
	

	return 0;
}