leetcode-223 Rectangle Area

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.

题目意思清楚，但是要注意特殊情况，就是不相交的特例。
经过观察发现，只要满足当一个矩形右上角的横纵坐标只要有一个小于另外一个矩形左下角的横纵坐标，那么就表示两个矩形不相交。其余情况，矩形相交，计算相交矩形坐标，减去面积即可。
时间36ms。
代码如下：

class Solution {public:    int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {        int s1=0, s2=0, s=0;        int  s3=0 ;        s1 = (C-A)*(D-B);        s2 = (G-E)*(H-F);        if(A >= G || B >= H || E >= C || F >= D)        s3=0;        else        {        int I, J , K , L;        I = A > E ? A : E;        J = B > F ? B : F;        K = C < G ? C : G;        L = D < H ? D : H;        s3 = (K-I)*(L-J);        }        s = s1+s2-s3;        return s;    }};