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.

 

1 public class Solution { 2     public int MinimumTotal(IList
     
      
       > triangle) { 3         int count = triangle.Count; 4          5         if (count == 0) return 0; 6          7         var dp = new int[count + 1]; 8          9         for (int i = count - 1; i >= 0; i--)10         {11             for (int j = 0; j < triangle[i].Count; j++)12             {13                 dp[j] = triangle[i][j] + Math.Min(dp[j], dp[j + 1]);14             }15         }16         17         return dp[0];        18     }19 }