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.

Java

public class Solution {
    public int minPathSum(int[][] grid) {
        if(grid.length < 1 || grid[0].length < 1) {
            return 0;
        }

        int row = grid.length;
        int col = grid[0].length;
        int[][] rst = new int[row][col];
        rst[0][0] = grid[0][0];

        for(int i = 1; i < col; i++) {
            rst[0][i] = rst[0][i - 1] + grid[0][i];
        }
        for(int i = 1; i < row; i++) {
            rst[i][0] = rst[i - 1][0] + grid[i][0];
        }

        for(int i = 1; i < row; i++) {
            for(int j = 1; j < col; j++) {
                rst[i][j] = Math.min(rst[i - 1][j], rst[i][j - 1]) + grid[i][j];
            }
        }

        return rst[row - 1][col - 1];
    }
}