@[hezi_j](/user/1158043) 应该是这样
```cpp
#include <bits/stdc++.h>
using namespace std;
int main()
{
int s, a, b;
double x, ans;//x是你的t那段时间走的距离
cin >> s >> a >> b;
x = (a + b) * 1.0 / (3 * a + b) * s;
ans = x / b + (s - x) / a;
printf("%.6lf", ans);
return 0;
}
```
by Hamdi @ 2024-05-03 14:13:25