A1 = ?

1
50.00
25.00
10.00
2
50.00
25.00
10.00
20.00

27.50
15.00

#include <stdio.h>
#include <string.h>

int main() {
    // freopen("stdin.txt", "r", stdin);
    int n, i;
    double c, C, a, b;

    while (scanf("%d", &n) == 1) {
        scanf("%lf%lf", &a, &b);
        C = 0.0;
        for (i = n; i >= 1; --i) {
            scanf("%lf", &c);
            C += i * c;
        }
        C *= 2.0;
        printf("%.2lf\n", (b - C + n * a) / (n + 1));
    }
    return 0;
}

HPUOJ1294 A1 = ?

原文：http://blog.csdn.net/chang_mu/article/details/42778497