LeetCode Triangle

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

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:
Bonus point if you are able to do this using only O(n) extra space, where n is the total number of rows in the triangle.

路徑只能選擇兩個子節點，採用dp，從下往上dp

public class Solution {
    public int minimumTotal(List<List<Integer>> triangle) {
        int row=triangle.size();
        int[] min=new int[row];
        for(int i=0;i<row;i++)
        	min[i]=triangle.get(row-1).get(i);
        for(int i=row-2;i>=0;i--)
        {
        	for(int j=0;j<triangle.get(i).size();j++)
        	{
        		min[j]=triangle.get(i).get(j)+Math.min(min[j], min[j+1]);
        	}
        }
        return min[0];
    }
}