Project Euler Problem 67 Solution in Multiple Languages

problem67.coffee

fs = require('fs')

triangle = fs.readFileSync('../triangle.txt', 'utf-8')
              .split('\r\n')
              .map((x) -> x.split(' ').map((y) -> +y))
              .reverse()
              .splice(1)

reduction = (prev, current) ->
  current.map (x, i) ->
    a = Math.max.apply(Math, [x + prev[i], x + prev[i + 1]])

console.log triangle.slice(1).reduce(reduction, triangle[0])

problem67.rb

triangle = File.open("../triangle.txt").map{|line|
  line.split.map(&:to_i)
}.reverse

puts triangle.slice(1, triangle.length).reduce(triangle.first) { |prev, new|
  index = -1
  new.map { |x|
    index += 1
    [x + prev[index], x + prev[index + 1]].max
  }
}.max