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.

Rectangle Area

Example:

Input: A = -3, B = 0, C = 3, D = 4, E = 0, F = -1, G = 9, H = 2
Output: 45

Note:

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

解题要点：

相交部分分成左右，上下四个点处理，如以下。

class Solution(object):
    def computeArea(self, A, B, C, D, E, F, G, H):
        """
        :type A: int
        :type B: int
        :type C: int
        :type D: int
        :type E: int
        :type F: int
        :type G: int
        :type H: int
        :rtype: int
        """
        a1 = (C - A) * (D - B)
        a2 = (G - E) * (H - F)
        left = max(A, E)
        right = max(left, min(C, G))
        down = max(B, F)
        top = max(down, min(D, H))
        return a1 + a2 - (right - left) * (top - down)