(leetcode) Set Matrix Zeroes

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

 1 class Solution {
 2 public:
 3     void setZeroes(vector<vector<int>>& matrix) {
 4         
 5         bool firstrow = false;
 6         bool firstcol = false;
 7         int rowsize = matrix.size();
 8         int colsize = matrix[0].size();
 9         if(rowsize == 0) return;
10         if(colsize == 0) return;
11         
12         for(int j = 0;j < colsize; ++j)
13         {
14             if(!matrix[0][j])
15                 firstrow = true;
16                 
17         }
18                 
19         for(int i = 0;i < rowsize; ++i)
20         {
21             if(!matrix[i][0])
22                 firstcol = true;
23                 
24         }
25         for(int i=0;i < rowsize;++i)
26         {
27             for(int j = 0;j < colsize;++j)
28             
29             {
30                 if(!matrix[i][j])
31                 {
32                     matrix[i][0] = matrix[0][j] = 0;
33                 }
34             }
35         }
36    
37         for(int j = 1;j < colsize; ++j)
38         {
39             if(!matrix[0][j])
40             {
41                 for(int i = 0;i < rowsize; ++i)
42                     matrix[i][j] = 0;
43             }
44         }
45         for(int i = 1;i < rowsize; ++i)
46         {
47             if(!matrix[i][0])
48             {
49                 for(int j = 0;j < colsize; ++j)
50                     matrix[i][j] = 0;
51             }
52         }
53         
54         if(firstrow)
55         {
56             for(int j =0; j < colsize;++j)
57             {
58                 matrix[0][j] = 0;
59             }
60         }
61         if(firstcol)
62         {
63             for(int i =0; i < rowsize;++i)
64             {
65                 matrix[i][0] = 0;
66             }
67         }
68     }
69 };