Computer >> Computer tutorials >  >> Programming >> C++

Circle and Rectangle Overlapping in C++

Suppose we have a circle represented as (radius, xc, yc), here (xc, yc) is the center coordinate of the circle. We also have an axis-aligned rectangle represented as (x1, y1, x2, y2), where (x1, y1) are the coordinates of the bottom-left corner, and (x2, y2) are the coordinates of the top-right corner of the rectangle. We have to check whether the circle and rectangle are overlapped or not.

So, if the input is like

Circle and Rectangle Overlapping in C++

then the output will be true.

To solve this, we will follow these steps −

  • Define a function eval(), this will take a, b, c,

  • return maximum of b and minimum of a and c

  • From the main method, do the following −

  • cdx := eval(cx, left, right), cdy := eval(cy, bottom, top)

  • rwid := right - left, rh := top - bottom

  • dx := cx - cdx, dy := cy - cdy

  • disSq := (dx * dx) + (dy * dy)

  • sqrRadius := (r * r)

  • return true when disSq <= sqrRadius, otherwise false

Example 

Let us see the following implementation to get better understanding −

#include <bits/stdc++.h>
using namespace std;
class Solution {
public:
   int eval(int a, int b, int c){
      return max(b, min(a, c));
   }
   bool checkOverlap(int r, int cx, int cy, int left, int bottom, int right, int top){
      double cdx = eval(cx, left, right);
      double cdy = eval(cy, bottom, top);
      double rwid = right - left;
      double rh = top - bottom;
      double dx = cx - cdx;
      double dy = cy - cdy;
      double disSq = (dx * dx) + (dy * dy);
      double sqrRadius = (r * r);
      return (disSq <= sqrRadius);
   }
};
main(){
   Solution ob;
   cout << (ob.checkOverlap(1, 0, 0, 1, -1, 3, 1));
}

Input

1, 0, 0, 1, -1, 3, 1

Output

1