Triangle ---DP

Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.

Have you met this question in a real interview? Yes
Example
For example, given the following triangle

[
[2],
[3,4],
[6,5,7],
[4,1,8,3]
]
The minimum path sum from top to bottom is 11 (i.e., 2 + 3 + 5 + 1 = 11).

Note

public class Solution {
    public int minimumTotal(int [][] triangle){
        if(triangle == null || triangle.length ==0)
            return -1;
        if(triangle[0]==null || triangle[0].length==0)
            return -1;

        int n = triangle.length;
        int [][] f = new int [n][n];


        for(int i =0; i<n; i++)
            f[n-1][i]=triangle[n-1][i];


        for(int i=n-2;i>=0;i--){
            for(int j =0;j<=i;j++){
                f[i][j]=Math.min(f[i+1][j],f[i+1][j+1]) +triangle[i][j];
            }
        }
        return f[0][0];
    }
}