20 lines
603 B
YAML
20 lines
603 B
YAML
title: Find the longest sequence using a starting number under one million.
|
|
url: http://projecteuler.net/problem=15
|
|
|
|
desc: |
|
|
Starting in the top left corner of a 22 grid, there are 6 routes (without backtracking) to the bottom right corner.
|
|
How many routes are there through a 2020 grid?
|
|
|
|
solution: |
|
|
(2n)!/n!^2 - Where n is the size of the grid -
|
|
|
|
todo: Find a more "programmable way" instead of this cheating mathsolution
|
|
|
|
solutions:
|
|
solve.php:
|
|
desc: Using BCMath to cope with large numbers
|
|
language: php
|
|
solve.rb:
|
|
desc: Basic solution
|
|
language: ruby
|