UVa 837 - Light and Transparencies

Accepted date: 2013-11-23
Ranking (as of 2013-11-23): 528 out of 672
Language: C++

/*
  UVa 837 - Light and Transparencies

  To build using Visual Studio 2012:
    cl -EHsc -O2 UVa_837_Light_and_Transparencies.cpp
*/

#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
using namespace std;

struct point {
  double x_;
  int tci_; // index to tcs[]
};

struct tc { // transparent coeficients
  bool effective_;
  double r_;
};

bool compare_point(const point& p, const point& q)
{
  return p.x_ < q.x_;
}

int main()
{
  int t;
  cin >> t;
  while (t--) {
    int nl;
    cin >> nl;
    int np = nl * 2;
    vector<point> points(np);
    vector<tc> tcs(nl);
    for (int i = 0; i < nl; i++) {
      double y1, y2;
      cin >> points[i * 2].x_ >> y1 >> points[i * 2 + 1].x_ >> y2 >> tcs[i].r_;
      points[i * 2].tci_ = points[i * 2 + 1].tci_ = i;
      tcs[i].effective_ = false;
    }
    sort(points.begin(), points.end(), compare_point);
    cout << np + 1 << endl;
    cout << fixed;
    for (int i = 0; i <= np; i++) {
      if (i)
        cout << setprecision(3) << points[i - 1].x_;
      else
          cout << "-inf";
      if (i < np)
          cout << ' ' << setprecision(3) << points[i].x_;
      else
        cout << " +inf";
      double pl = 1.0; // percentage of light
      if (i && i < np) {
        for (int j = 0; j < nl; j++)
          if (tcs[j].effective_)
            pl *= tcs[j].r_;
      }
      cout << ' ' << setprecision(3) << pl << endl;
      if (i < np)
        tcs[points[i].tci_].effective_ = !tcs[points[i].tci_].effective_;
    }
    if (t)
      cout << endl;
  }
  return 0;
}