Problem Triangle

Problem Description:

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

Solution:

    public int minimumTotal(List<List<Integer>> triangle) {
        for (int i = triangle.size()- 1; i >= 0; i--) {
            minimumTriangle(triangle, i);
        }
        return triangle.get(0).get(0);
    }
    
    public void minimumTriangle(List<List<Integer>> triangle, int row) {
        if (row == triangle.size() - 1)
            return;
        int min = Integer.MAX_VALUE;
        for (int i = 0; i < triangle.get(row).size(); i++) {
            triangle.get(row).set(i, triangle.get(row).get(i) + Math.min(triangle.get(row+1).get(i), triangle.get(row+1).get(i+1)));
        }
    }