UVA 10491 Cows and Cars

UVA_10491

    公式还是比较容易推的。

#include<stdio.h>
#include<string.h>
double COWS, CARS, SHOW;
int main()
{
    while(scanf("%lf%lf%lf", &COWS, &CARS, &SHOW) == 3)
        printf("%.5lf\n", (COWS * CARS + CARS * (CARS - 1)) / (CARS + COWS) / (CARS + COWS - SHOW - 1));
    return 0;
}