content: {- 
   - Solution to Project Euler problem 18
   - Copyright (c) Project Nayuki. All rights reserved.
   - 
   - https://www.nayuki.io/page/project-euler-solutions
   - https://github.com/nayuki/Project-Euler-solutions
   -}
  
  
  {- 
   - If we start at a particular cell in the triangle, what is the maximum path total?
   - If the cell is in the bottom row, then it is simply the cell's value. Otherwise the answer
   - is the cell's value plus either {the maximum path total of the cell down and to the left}
   - or {the maximum path total of the cell down and to the right}, whichever is greater.
   -}
  
  main = putStrLn (show ans)
  ans = maxPath 0 0
  
  maxPath i j = (triangle !! i !! j) +
  	(if i + 1 < length triangle
  		then max (maxPath (i + 1) j) (maxPath (i + 1) (j + 1))
  		else 0)
  
  triangle = [
  	[75],
  	[95,64],
  	[17,47,82],
  	[18,35,87,10],
  	[20,04,82,47,65],
  	[19,01,23,75,03,34],
  	[88,02,77,73,07,63,67],
  	[99,65,04,28,06,16,70,92],
  	[41,41,26,56,83,40,80,70,33],
  	[41,48,72,33,47,32,37,16,94,29],
  	[53,71,44,65,25,43,91,52,97,51,14],
  	[70,11,33,28,77,73,17,78,39,68,17,57],
  	[91,71,52,38,17,14,91,43,58,50,27,29,48],
  	[63,66,04,68,89,53,67,30,73,16,69,87,40,31],
  	[04,62,98,27,23, 9,70,98,73,93,38,53,60,04,23]]
  