UVA 10522 Height to Area（知三角形三高求面积）

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 int main()
 4 {
 5     int n;
 6     scanf("%d",&n);
 7     double ha, hb, hc, a, b, c;
 8     while(~scanf("%lf %lf %lf",&ha,&hb,&hc))
 9     {
10         a = 2.0 / ha;
11         b = 2.0 / hb ;
12         c = 2.0 / hc;
13         if(a <= 0.0 || b <= 0.0 || c <= 0.0 || a >= b+c || b >= a+c || c >= a+b )
14         {
15             printf("These are invalid inputs!\n");
16         }
17         else {
18             double p = (a + b + c)*0.5;
19             double s = p * (p - a)*(p - b)*(p - c);
20             printf("%.3f\n",sqrt(1.0 / s));
21         }
22     }
23     return 0;
24 }