UVa 11326 - Laser Pointer

Accepted date: 2018-01-01
Run Time: 0.020
Ranking (as of 2018-01-02): 12 out of 394
Language: C++11

/*
  UVa 11326 - Laser Pointer

  To build using Visual Studio 2015:
    cl -EHsc -O2 UVa_11326_Laser_Pointer.cpp
*/

#include <limits>
#include <cstdio>
#include <cmath> // C++11
using namespace std;

int main()
{
  const double pi = 2.0 * acos(0.0);
  const double epsilon = numeric_limits<double>::epsilon();
  int nr_cases;
  scanf("%d", &nr_cases);
  while (nr_cases--) {
    double L, W, theta;
    scanf("%lf %lf %lf", &L, &W, &theta);
    double t = tan(theta * pi / 180.0), r = 1.0;
    if (t > W / L) {
      double x = W / t, y, A;
      int n = static_cast<int>(L / x + epsilon);
      if (n & 1) {
        y = (n + 1) * W - L * t;
        A = (n + 1) * hypot(x, W) - hypot((n + 1) * x - L, y);
      }
      else {
        y = L * t - W * n;
        A = hypot(x, W) * n + hypot(L - n * x, y);
      }
      r = A / hypot(L, y);
    }
    printf("%.3lf\n", r);
  }
  return 0;
}