Problem: Rectangle Overlap

Posted by Marcy on February 18, 2015

Question

A rectangle is represented as a list [x1, y1, x2, y2], where (x1, y1) are the coordinates of its bottom-left corner, and (x2, y2) are the coordinates of its top-right corner.

Two rectangles overlap if the area of their intersection is positive. To be clear, two rectangles that only touch at the corner or edges do not overlap.

Given two (axis-aligned) rectangles, return whether they overlap.

Example 1:

Input: rec1 = [0,0,2,2], rec2 = [1,1,3,3]
Output: true

Example 2:

Input: rec1 = [0,0,1,1], rec2 = [1,0,2,1]
Output: false

Code

class Solution {
    public boolean isRectangleOverlap(int[] rec1, int[] rec2) {
        if(rec1[0] >= rec2[2] || rec2[0] >= rec1[2]) return false;
        if(rec1[1] >= rec2[3] || rec2[1] >= rec1[3]) return false;
        return true;
    }
}

Performance

O(1)