73. 矩阵置零 @Python @Go

原题

https://leetcode.cn/problems/set-matrix-zeroes/description/

思路

遍历

复杂度

时间：O(m * n)
空间：O(m * n)

Python代码

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])
        rows = set()
        cols = set()
        for i in range(m):
            for j in range(n):
                if matrix[i][j] == 0:
                    rows.add(i)
                    cols.add(j)
        for r in rows:
            matrix[r] = [0] * n 
        for c in cols:
            for r in range(m):
                matrix[r][c] = 0

Go代码

func setZeroes(matrix [][]int) {
	m, n := len(matrix), len(matrix[0])
	rows, cols := map[int]bool{}, map[int]bool{}
	// 记录元素0所在的位置
	for i := 0; i < m; i++ {
		for j := 0; j < n; j++ {
			if matrix[i][j] == 0 {
				rows[i] = true
				cols[j] = true
			}
		}
	}
	for r := range rows {
		matrix[r] = make([]int, n)
	}
	for c := range cols {
		for r := 0; r < m; r++ {
			matrix[r][c] = 0
		}
	}
}