[Leetcode] Minimum Path Sum

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.

Solution: dp

public class Solution {
    public int minPathSum(int[][] grid) {
        int M=grid.length;
        int N=grid[0].length;
        int[][] dp=new int[M][N];
        dp[0][0]=grid[0][0];
        for(int i=1;i<M;++i){
            dp[i][0]=dp[i-1][0]+grid[i][0];
        }
        for(int i=1;i<N;++i){
            dp[0][i]=dp[0][i-1]+grid[0][i];
        }
        for(int i=1;i<M;++i){
            for(int j=1;j<N;++j){
                dp[i][j]=Math.min(dp[i-1][j],dp[i][j-1])+grid[i][j];
            }
        }
        return dp[M-1][N-1];
    }
}