[leetcode]Minimum Path Sum

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.

 算法思路：

简单二维DP。

代码如下：

public class Solution {
    public int minPathSum(int[][] grid) {
        if(grid == null || grid.length == 0) return 0;
        int height = grid.length;
        int width = grid[0].length;
        for(int i = 1; i < width; i++){
            grid[0][i] += grid[0][i - 1];
        }
        for(int i = 1; i < height;i++){
            grid[i][0] += grid[i - 1][0];
        }
        for(int i = 1; i < height; i++){
            for(int j = 1; j < width; j++){
                grid[i][j] += Math.min(grid[i - 1][j],grid[i][j - 1]);
            }
        }
        return grid[height - 1][width - 1];
    }
}