[leetcode] Minimum Path Sum

 1 public class Solution {
 2     public int minPathSum(int[][] grid) {
 3         if (grid == null || grid.length == 0 || grid[0].length == 0)
 4             return 0;
 5         int m = grid.length;
 6         int n = grid[0].length;
 7         int[][] len = new int[m][n];
 8 
 9         int i;
10         int sum = 0;
11         for (i = 0; i < m; i++) {
12             sum += grid[i][0];
13             len[i][0] = sum;
14         }
15         sum = 0;
16         for (i = 0; i < n; i++) {
17             sum += grid[0][i];
18             len[0][i] = sum;
19         }
20         int j;
21         for (i = 1; i < m; i++) {
22             for (j = 1; j < n; j++) {
23                 if (len[i][j] == 0) {
24                     len[i][j] = (len[i - 1][j] < len[i][j - 1] ? len[i - 1][j]
25                             : len[i][j - 1]) + grid[i][j];
26                 }
27 
28             }
29 
30         }
31 
32         return len[m - 1][n - 1];
33     }
34 
35     public static void main(String[] args) {
36         int[][] grid = { { 1 } };
37         System.out.println(new Solution().minPathSum(grid));
38     }
39 }