Set Matrix Zeroes

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.

click to show follow up.

Follow up:

Did you use extra space?
A straight forward solution using O(mn) space is probably a bad idea.
A simple improvement uses O(m + n) space, but still not the best solution.
Could you devise a constant space solution?

分析：将数组中为0元素所在的行和列都置0。首先找到这些元素，分别开两个数组记录所在行和列，将这些行和列分别置0

运行时间：87ms

 

 1 class Solution {
 2 public:
 3     void setZeroes(vector<vector<int>>& matrix) {
 4         int row = matrix.size();
 5         int col = matrix[0].size();
 6         
 7         vector<int> vRow(row, 0);
 8         vector<int> vCol(col, 0);
 9         for(int i = 0; i < row; i++){
10             for(int j = 0; j < col; j++){
11                 if(matrix[i][j] == 0){
12                     vRow[i] = 1;
13                     vCol[j] = 1;
14                 }
15             }
16         }
17         for(int i = 0; i < row; i++){
18             if(vRow[i] == 1){
19                 for(int j = 0; j < col; j++) matrix[i][j] = 0;
20             }
21         }
22         for(int j = 0; j < col; j++){
23             if(vCol[j] == 1){
24                 for(int i = 0; i < row; i++) matrix[i][j] = 0;
25             }
26         }
27         return;
28     }
29 };