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.

想找出重合部分 ，再将总的部分减去场合的面积。

public class Solution {

    public int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {
            int l=0;
            int d=0;
            l=A<=E?helper(A,C,E,G):helper(E,G,A,C);
            d=B<=F?helper(B,D,F,H):helper(F,H,B,D);
            return total(A,B,C,D)+total(E,F,G,H)-l*d;
    }
    public int helper(int a,int b,int c,int d){
    return b<c?0:(b<d?b:d)-c;
    }
    public int total(int a,int b,int c,int d){
      return (c-a)*(d-b);
    }
}