73. Set Matrix Zeroes刷题笔记

用了set来投机取巧

class Solution:
    def setZeroes(self, matrix: List[List[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        m = len(matrix)
        n = len(matrix[0])
        cm = set()
        cn = set()
        for i in range(m):
            for j in range(n):
                if matrix[i][j] == 0:
                    cm.add(i)
                    cn.add(j)
        for i in cm:
            for j in range(n):
                matrix[i][j] = 0
        for j in cn:
            for i in range(m):
                matrix[i][j] = 0