P1223 排队接水题解

题目传递门

#include <bits/stdc++.h>

using namespace std;
typedef long long LL;
const int N = 1010;

struct water {
    int num, time;
} p[N];

bool cmp(const water &a, const water &b) {
    if (a.time != b.time) return a.time < b.time;//首先按接水时间排序，谁小，谁在前
    return a.num < b.num;//如果接水时间一样长，那么谁号小谁靠前
}

int n;
LL sum;

int main() {
    //输入
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%d", &p[i].time);
        p[i].num = i;
    }
    //排序
    sort(p + 1, p + n + 1, cmp);

    for (int i = 1; i <= n; i++) {
        printf("%d ", p[i].num); //第几号
        sum += (n - i) * p[i].time; //这个n-i用的妙
    }
    printf("\n%.2lf", 1.0 * sum / n);
    return 0;
}