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.
Code
public class Solution {
public int minPathSum(int[][] grid) {
if (grid==null || grid.length==0 || grid[0].length==0) return 0;
int m = grid.length;
int n = grid[0].length;
int[][] dp = new int[m][n];
for (int i=0; i<m; i++){
for (int j=0; j<n; j++){
if (i==0 && j==0) {dp[i][j] = grid[i][j];}
else if (i==0) {dp[i][j] = dp[i][j-1] + grid[i][j];}
else if (j==0) {dp[i][j] = dp[i-1][j] + grid[i][j];}
else {dp[i][j] = Math.min(dp[i-1][j], dp[i][j-1]) + grid[i][j];}
}
}
return dp[m-1][n-1];
}
}