Codewars. C#

pyramid-slide-down-4kyu.cs

using System;
using System.Linq;

public class PyramidSlideDown
{
    public static int LongestSlideDown(int[][] pyramid)
    {
      for (int i = 1; i < pyramid.Length; i++)
          for (int j = 0; j < pyramid[i].Length; j++)
              if (j == 0) { pyramid[i][j] += pyramid[i - 1][j]; }
              else if (j == pyramid[i].Length -1) { pyramid[i][j] += pyramid[i - 1][j - 1]; }
              else {pyramid[i][j] += Math.Max(pyramid[i - 1][j], pyramid[i - 1][j - 1]);}

      return pyramid[pyramid.Length - 1].Max();
    }
}