poj2940

简单题

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
using namespace std;

#define maxn 100005

int n, f[maxn];

void input()
{
    for (int i = 0; i < n; i++)
        scanf("%d", &f[i]);
}

void work()
{
    int i = 0, j = 0;
    long long ans = 0;
    while (1)
    {
        while (i < n && f[i] <= 0)
            i++;
        while (j < n && f[j] >= 0)
            j++;
        if (j >= n || i >= n)
            break;
        int x = min(f[i], -f[j]);
        f[i] -= x;
        f[j] += x;
        ans += x * abs(i - j);
    }
    printf("%lld\n", ans);
}

int main()
{
    //freopen("t.txt", "r", stdin);
    while (scanf("%d", &n), n)
    {
        input();
        work();
    }
    return 0;
}