LeetCode:Rectangle Area

Rectangle Area

Total Accepted: 23524  Total Submissions: 84978  Difficulty: Easy

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.

思路：

两种情况：1）矩形相交；2）矩形不相交。

1）不相交：当A>=E或C<=E或B>=H或D<=H。

2）相交：求相交覆盖矩形的左下(x1,y2)、右上坐标(x2,y2)：

    x1 = max(A,E)；y1 = max(B,F);

    x2 = min(C,G)；y2 = min(D,H);

所有的相交情况都符合上式。

code:

class Solution {
public:
    int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {
        int total = area(A,B,C,D)+area(E,F,G,H);
        if(A>=G || C<=E || B>=H || D<=F) {
            return total;
        }else{
            int x1=max(A,E);
            int y1=max(B,F);
            int x2=min(C,G);
            int y2=min(D,H);
            return total - area(x1,y1,x2,y2);
        }
    }
    int area(int x1,int y1, int x2, int y2) 
    {
         return abs((x1-x2)*(y2-y1));
    }
};