C++ | Leetcode C++题解之第391题完美矩形

题目：

题解：

typedef pair Point;

class Solution {
public:
    bool isRectangleCover(vector>& rectangles) {
        long area = 0;
        int minX = rectangles[0][0], minY = rectangles[0][1], maxX = rectangles[0][2], maxY = rectangles[0][3];
        map cnt;
        for (auto & rect : rectangles) {
            int x = rect[0], y = rect[1], a = rect[2], b = rect[3];
            area += (long) (a - x) * (b - y);

            minX = min(minX, x);
            minY = min(minY, y);
            maxX = max(maxX, a);
            maxY = max(maxY, b);

            Point point1({x, y});
            Point point2({x, b});
            Point point3({a, y});
            Point point4({a, b});

            cnt[point1] += 1;
            cnt[point2] += 1;
            cnt[point3] += 1;
            cnt[point4] += 1;
        }

        Point pointMinMin({minX, minY});
        Point pointMinMax({minX, maxY});
        Point pointMaxMin({maxX, minY});
        Point pointMaxMax({maxX, maxY});
        if (area != (long long) (maxX - minX) * (maxY - minY) || !cnt.count(pointMinMin) || !cnt.count(pointMinMax) || !cnt.count(pointMaxMin) || !cnt.count(pointMaxMax)) {
            return false;
        }

        cnt.erase(pointMinMin);
        cnt.erase(pointMinMax);
        cnt.erase(pointMaxMin);
        cnt.erase(pointMaxMax);

        for (auto & entry : cnt) {
            int value = entry.second;
            if (value != 2 && value != 4) {
                return false;
            }
        }
        return true;
    }
};