LeetCode题解(0391)：完美矩形(Python)

题目：​​原题链接​​（困难）

标签：扫描线算法、数学

解法一：

class Solution:
    def isRectangleCover(self, rectangles: List[List[int]]) -> bool:
        count1 = collections.Counter()
        mx1, my1, mx2, my2 = float("inf"), float("inf"), float("-inf"), float("-inf")
        space = 0
        for x1, y1, x2, y2 in rectangles:
            count1[(x1, y1)] += 1
            count1[(x1, y2)] += 1
            count1[(x2, y1)] += 1
            count1[(x2, y2)] += 1
            space += (x2 - x1) * (y2 - y1)
            mx1, my1, mx2, my2 = min(mx1, x1), min(my1, y1), max(mx2, x2), max(my2, y2)
        count2 = collections.Counter(count1.values())
        return (count2[1] == 4
                and space == (mx2 - mx1) * (my2 - my1)
                and len(rectangles) == len(set(tuple(elem) for elem in rectangles))
                and count1[(mx1, my1)] == 1 and count1[(mx1, my2)] == 1
                and count1[(mx2, my1)] == 1 and count1[(mx2, my2)] == 1)