1 public class Solution { 2     /** 3      * @param grid: a list of lists of integers. 4      * @return: An integer, minimizes the sum of all numbers along its path 5      */ 6     public int minPathSum(int[][] grid) { 7         int rowNum = grid.length; 8         if (rowNum==0) return 0; 9         int colNum = grid[0].length;10         if (colNum==0) return 0;11         12         int[][] sum = new int[rowNum][colNum];13         sum[0][0] = grid[0][0];14         for (int i=1;i<rowNum;i++) sum[i][0] = sum[i-1][0]+grid[i][0];15         for (int i=1;i<colNum;i++) sum[0][i] = sum[0][i-1]+grid[0][i];16         17         for (int i=1;i<rowNum;i++)18             for (int j=1;j<colNum;j++){19                 sum[i][j] = Math.min(sum[i-1][j],sum[i][j-1])+grid[i][j];20             }21                 22         return sum[rowNum-1][colNum-1];23     }24 }