#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[])
{
double a, b, c;
while (cin >> a >> b >> c)
printf("%.5f\n", b * (a + b - 1) / (a + b) / (a + b - c - 1));
return 0;
}
照书上分析就好
#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[])
{
double a, b, c;
while (cin >> a >> b >> c)
printf("%.5f\n", b * (a + b - 1) / (a + b) / (a + b - c - 1));
return 0;
}
照书上分析就好