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

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
      
       
        >& matrix) { 4         int row = matrix.size(); 5         int col = matrix[0].size(); 6          7         vector
        
          vRow(row, 0); 8         vector
         
           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 };