零矩阵

题目

https://leetcode.cn/leetbook/read/array-and-string/ciekh/

编写一种算法，若 M × N 矩阵中某个元素为 0，则将其所在的行与列清零。

实现

/**
 * @param {number[][]} matrix
 * @return {void} Do not return anything, modify matrix in-place instead.
 */
var setZeroes = function (matrix) {
    // 1.使用rows和cols记录
    let m = matrix.length, n = matrix[0].length;
    const rows = new Set()
    const cols = new Set()
    for (let i = 0; i < m; i++) {
        for (let j = 0; j < n; j++) {
            if (matrix[i][j] == 0) {
                rows.add(i);
                cols.add(j);
            }
        }
    }
    for (let i = 0; i < m; i++) {
        for (let j = 0; j < n; j++) {
            if (rows.has(i) || cols.has(j)) {
                matrix[i][j] = 0;
            }
        }
    }
};