LeetCode - Refresh - Set Matrix Zeroes

You can use two array to record the zeros. Also you can do it in memory:

 1 class Solution {
 2 public:
 3     void setZeroes(vector<vector<int> > &matrix) {
 4         if (matrix.size() == 0) return;
 5         int n = matrix.size(), m = matrix[0].size();
 6         bool row = false, column = false;
 7         for (int i = 0; i < n; i++) {
 8             if (matrix[i][0] == 0) {
 9                 row = true;
10                 break;
11             }
12         }
13         for (int i = 0; i < m; i++) {
14             if (matrix[0][i] == 0) {
15                 column = true;
16                 break;
17             }
18         }
19         for (int i = 1; i < n; i++) {
20             for (int j = 1; j < m; j++) {
21                 if (matrix[i][j] == 0) {
22                     matrix[i][0] = 0;
23                     matrix[0][j] = 0;
24                 }
25             }
26         }
27         for (int i = 1; i < n; i++) {
28             for (int j = 1; j < m; j++) {
29                 if (matrix[i][0] == 0 || matrix[0][j] == 0) {
30                     matrix[i][j] = 0;
31                 }
32             }
33         }
34         if (row) {
35             for (int i = 0; i < n; i++) {
36                 matrix[i][0] = 0;
37             }
38         }
39         if (column) {
40             for (int i = 0; i < m; i++) {
41                 matrix[0][i] = 0;
42             }
43         }
44     }
45 };

posted on 2015-03-23 13:50 keepshuatishuati 阅读(107) 评论(0) 收藏举报