给定两个矩形,判断这两个矩形是否有重叠。
样例
给定 l1 = [0, 8]
, r1 = [8, 0]
, l2 = [6, 6]
, r2 = [10, 0]
, 返回 true
给定 l1 = [0, 8]
, r1 = [8, 0]
, l2 = [9, 6]
, r2 = [10, 0]
, 返回 false
解题思路:
一开始想了很多种情况,但是这样太复杂了。由于这里矩形都是与坐标轴平行的,所以分别投影到x轴与y轴,判断投影后的线段是否重合即可。
首先,比如一维的情况,两条线段[l1,r1][l2,r2]相重叠,必须满足max(l1,l2)<=min(r1,r2),然后同理推广到x轴与y轴投影中。
/**
* Definition for a point.
* struct Point {
* int x;
* int y;
* Point() : x(0), y(0) {}
* Point(int a, int b) : x(a), y(b) {}
* };
*/
class Solution {
public:
/**
* @param l1: top-left coordinate of first rectangle
* @param r1: bottom-right coordinate of first rectangle
* @param l2: top-left coordinate of second rectangle
* @param r2: bottom-right coordinate of second rectangle
* @return: true if they are overlap or false
*/
bool doOverlap(Point &l1, Point &r1, Point &l2, Point &r2)
{
// write your code here
return max(l1.x,l2.x)<=min(r1.x,r2.x) && max(r1.y,r2.y)<=min(l1.y,l2.y);
}
};