|
| 1 | +### 题目描述 |
| 2 | + |
| 3 | +这是 LeetCode 上的 **[面试题 01.08. 零矩阵](https://leetcode.cn/problems/zero-matrix-lcci/solution/by-ac_oier-0lo0/)** ,难度为 **中等**。 |
| 4 | + |
| 5 | +Tag : 「模拟」 |
| 6 | + |
| 7 | + |
| 8 | + |
| 9 | +编写一种算法,若 $M \times N$ 矩阵中某个元素为 $0$,则将其所在的行与列清零。 |
| 10 | + |
| 11 | +示例 1: |
| 12 | +``` |
| 13 | +输入: |
| 14 | +[ |
| 15 | + [1,1,1], |
| 16 | + [1,0,1], |
| 17 | + [1,1,1] |
| 18 | +] |
| 19 | +
|
| 20 | +输出: |
| 21 | +[ |
| 22 | + [1,0,1], |
| 23 | + [0,0,0], |
| 24 | + [1,0,1] |
| 25 | +] |
| 26 | +``` |
| 27 | +示例 2: |
| 28 | +``` |
| 29 | +输入: |
| 30 | +[ |
| 31 | + [0,1,2,0], |
| 32 | + [3,4,5,2], |
| 33 | + [1,3,1,5] |
| 34 | +] |
| 35 | +
|
| 36 | +输出: |
| 37 | +[ |
| 38 | + [0,0,0,0], |
| 39 | + [0,4,5,0], |
| 40 | + [0,3,1,0] |
| 41 | +] |
| 42 | +``` |
| 43 | + |
| 44 | +--- |
| 45 | + |
| 46 | +### 模拟 |
| 47 | + |
| 48 | +根据题意进行模拟。 |
| 49 | + |
| 50 | +Java 代码: |
| 51 | +```Java |
| 52 | +class Solution { |
| 53 | + public void setZeroes(int[][] mat) { |
| 54 | + int n = mat.length, m = mat[0].length; |
| 55 | + boolean[] rows = new boolean[n], cols = new boolean[m]; |
| 56 | + for (int i = 0; i < n; i++) { |
| 57 | + for (int j = 0; j < m; j++) { |
| 58 | + if (mat[i][j] == 0) rows[i] = cols[j] = true; |
| 59 | + } |
| 60 | + } |
| 61 | + for (int i = 0; i < n; i++) { |
| 62 | + for (int j = 0; j < m; j++) { |
| 63 | + if (rows[i] || cols[j]) mat[i][j] = 0; |
| 64 | + } |
| 65 | + } |
| 66 | + } |
| 67 | +} |
| 68 | +``` |
| 69 | +TypeScript 代码: |
| 70 | +```TypeScript |
| 71 | +function setZeroes(mat: number[][]): void { |
| 72 | + const n = mat.length, m = mat[0].length |
| 73 | + const rows = new Array<boolean>(n).fill(false), cols = new Array<boolean>(m).fill(false) |
| 74 | + for (let i = 0; i < n; i++) { |
| 75 | + for (let j = 0; j < m; j++) { |
| 76 | + if (mat[i][j] == 0) rows[i] = cols[j] = true |
| 77 | + } |
| 78 | + } |
| 79 | + for (let i = 0; i < n; i++) { |
| 80 | + for (let j = 0; j < m; j++) { |
| 81 | + if (rows[i] || cols[j]) mat[i][j] = 0 |
| 82 | + } |
| 83 | + } |
| 84 | +}; |
| 85 | +``` |
| 86 | +Python 代码: |
| 87 | +```Python |
| 88 | +class Solution: |
| 89 | + def setZeroes(self, mat: List[List[int]]) -> None: |
| 90 | + n, m = len(mat), len(mat[0]) |
| 91 | + rows, cols = [False] * n, [False] * m |
| 92 | + for i in range(n): |
| 93 | + for j in range(m): |
| 94 | + if mat[i][j] == 0: |
| 95 | + rows[i] = cols[j] = True |
| 96 | + for i in range(n): |
| 97 | + for j in range(m): |
| 98 | + mat[i][j] = 0 if rows[i] or cols[j] else mat[i][j] |
| 99 | +``` |
| 100 | +* 时间复杂度:$O(n \times m)$ |
| 101 | +* 空间复杂度:$O(n + m)$ |
| 102 | + |
| 103 | +--- |
| 104 | + |
| 105 | +### 最后 |
| 106 | + |
| 107 | +这是我们「刷穿 LeetCode」系列文章的第 `No.面试题 01.08` 篇,系列开始于 2021/01/01,截止于起始日 LeetCode 上共有 1916 道题目,部分是有锁题,我们将先把所有不带锁的题目刷完。 |
| 108 | + |
| 109 | +在这个系列文章里面,除了讲解解题思路以外,还会尽可能给出最为简洁的代码。如果涉及通解还会相应的代码模板。 |
| 110 | + |
| 111 | +为了方便各位同学能够电脑上进行调试和提交代码,我建立了相关的仓库:https://github.com/SharingSource/LogicStack-LeetCode 。 |
| 112 | + |
| 113 | +在仓库地址里,你可以看到系列文章的题解链接、系列文章的相应代码、LeetCode 原题链接和其他优选题解。 |
| 114 | + |
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