UVA 142 : Mouse Clicks

mc.cpp

#include <iostream>
#include <vector>
#include <climits>
#include <cstdio>
#include <iomanip>

using namespace std;

class Rect
{
public:
    Rect(int left, int top, int right, int bottom):
        x1(left), x2(right), y1(top), y2(bottom)
    {
    }

    bool isInside(int px, int py) const
    {
      return (px >= x1 && px <= x2 && py >= y1 && py <= y2);
    }
    int x1;
    int x2;
    int y1;
    int y2;
};

class Icon
{
public:
    Icon(int px, int py): x(px), y(py), visible(true)
    {
    }

    int distance(int px, int py)
    {
        return (x-px)*(x-px)+(y-py)*(y-py);
    }
    bool visible;
    int x;
    int y;
};

class Window
{
public:
  Window():m_bRemoveHiddenIcon(false)
  {
  }
   
  void InsertRect(int l, int t, int r, int b)
  {
    char id = static_cast<char>(m_rects.size() + 65);
    Rect rect(l,t,r,b);
    m_rects.push_back(rect);
  }

  void InsertIcon(int px, int py)
  {
    int id = (int) m_icons.size() + 1;
    Icon icon(px,py);
    m_icons.push_back(icon);
  }

  bool hasRemoveHiddenIcons() const
  {
    return m_bRemoveHiddenIcon;
  }

  void RemoveHiddenIcons()
  {
    for (size_t i=0; i<m_icons.size(); ++i)
      {
	for (size_t j=0; j<m_rects.size(); ++j)
	  {
	    if (m_rects[j].isInside(m_icons[i].x, m_icons[i].y))
	      {
		m_icons[i].visible = false;
		break;
	      }
	  }
      }
    m_bRemoveHiddenIcon = true;
  }

  void PrintSelection(int mx, int my)
  {
    for (int i=(int)m_rects.size()-1; i>=0; --i)
      {
	if (m_rects[i].isInside(mx,my))
	  {
	    cout << (char)(i+65) << endl;
	    return;
	  }
      }

    // there is always an icon
    std::vector<int> iconId;        
    int dist = INT_MAX;
    for (size_t i=0; i<m_icons.size(); ++i)
      {
	if (!m_icons[i].visible)
	  continue;

	int newDist = m_icons[i].distance(mx,my);
	if (newDist == dist)
	  iconId.push_back(i+1);

	else if (newDist < dist) {
	  dist = newDist;
	  iconId.clear();
	  iconId.push_back(i+1);
	}

      }

    for (size_t i=0; i<iconId.size(); i++) {
      cout << setw(3) << iconId[i];
    }
    cout << endl;
  }
  bool m_bRemoveHiddenIcon;
  std::vector<Rect> m_rects;
  std::vector<Icon> m_icons; // only visible icons
};

int main(int argc, const char * argv[])
{
    Window w;
    bool doneProcessing = false;
    char t;
    char line[255];

    while (gets(line)) {
      switch(line[0]) {
      case '#':
	return 0;
      case 'I':
	{
	  int x, y;
	  sscanf(&line[1],"%d %d",&x,&y);
	  w.InsertIcon(x,y);
	}
	break;
      case 'R':
	{
	  int l, t, r, b;
	  sscanf(&line[1],"%d %d %d %d", &l, &t, &r, &b);
	  w.InsertRect(l, t, r, b);
	}
	break;
      case 'M':
	{
	  if (!w.hasRemoveHiddenIcons()) {
	    w.RemoveHiddenIcons();
	  }
	  int x, y;
	  sscanf(&line[1],"%d %d",&x,&y);
	  w.PrintSelection(x,y);
	}
	break;
      }
    }
    return 0;
}