【LeetCode】223. Rectangle Area 解题小结

题目：

Find the total area covered by two rectilinear rectangles in a 2D plane.

Each rectangle is defined by its bottom left corner and top right corner as shown in the figure.

Assume that the total area is never beyond the maximum possible value of int.

 首先判断两个矩形是否相交，不相交直接返回两个矩形面积，相交的话需要计算相交部分的左下点和右上点的坐标，用两矩形面积减去相交面积就可以了。

class Solution {
public:
    int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {
        int recArea = area(A,B,C,D) + area(E,F,G,H);
        if (A >= G || C <= E || D <= F || B >= H) return recArea;
        
        int recMinx = max(A,E);
        int recMiny = max(B,F);
        int recMaxx = min(C,G);
        int recMaxy = min(D,H);
        
        return recArea - area(recMinx, recMiny, recMaxx, recMaxy);
    }
    
    int area(int A, int B, int C, int D){
        return (C-A)*(D-B);
    }
};