Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.Note: You can only move either down or right at any point in time.

/** * Created by yuanxu on 17/4/13. */public class DP64 {    public static int minPathSum(int[][] grid) {        int m = grid.length;        int n = grid[0].length;        int res[][] = new int[m][n];        // boundary conditions        res[0][0] = grid[0][0];        for (int i=1; i<m; i++) {            res[i][0] = grid[i][0] + res[i-1][0];        }        for (int j=1; j<n; j++) {            res[0][j] = grid[0][j] + res[0][j-1];        }        // dp        for (int i=1; i<m; i++) {            for (int j=1; j<n; j++) {                res[i][j] = grid[i][j] + (res[i-1][j] < res[i][j-1] ? res[i-1][j] : res[i][j-1]);            }        }        return res[m-1][n-1];    }    public  static void main(String[] args) {        int grid[][] = {{1,2},{1,1}};        System.out.println(minPathSum(grid));    }}

public class Solution {    public int minPathSum(int[][] grid) {        int m = grid.length;// row        int n = grid[0].length; // column        for (int i = 0; i < m; i++) {            for (int j = 0; j < n; j++) {                if (i == 0 && j != 0) {                    grid[i][j] = grid[i][j] + grid[i][j - 1];                } else if (i != 0 && j == 0) {                    grid[i][j] = grid[i][j] + grid[i - 1][j];                } else if (i == 0 && j == 0) {                    grid[i][j] = grid[i][j];                } else {                    grid[i][j] = Math.min(grid[i][j - 1], grid[i - 1][j])                            + grid[i][j];                }            }        }        return grid[m - 1][n - 1];    }}