leetcode. Minimum Path Sum

 1 int minPathSum(vector<vector<int> > &grid) 
 2     {
 3         int m = grid.size();
 4         if (m <= 0)
 5             return 0;
 6         int n = grid[0].size(), i, j, result;
 7         int **path_arr = new int* [m];
 8         for (i = 0; i < m; i++)
 9         {
10             path_arr[i] = new int[n];
11         }
12             
13         for (i = 0; i < m; i++)
14         {
15             for (j = 0; j < n; j++)
16             {
17                 if (i == 0 && j == 0)
18                     path_arr[i][j] = grid[i][j];
19                 else if (i == 0 && j > 0)
20                     path_arr[i][j] = grid[i][j] + path_arr[i][j - 1];
21                 else if (i > 0 && j == 0)
22                     path_arr[i][j] = grid[i][j] + path_arr[i - 1][j];
23                 else
24                     path_arr[i][j] = min(path_arr[i - 1][j], path_arr[i][j - 1]) + grid[i][j];
25             }
26         }
27         result = path_arr[m - 1][n - 1];
28         for (i = 0; i < m; i++)
29         {
30             delete[] path_arr[i];
31         }
32         delete[] path_arr;
33         return result;
34     }