Solved ProjectEuler\020: php, ruby

ProjectEuler/020/desc.yml

@@ -0,0 +1,18 @@
+title: Find the sum of digits in 100!
+url: http://projecteuler.net/problem=20
+
+desc: |
+  n! means n * (n - 1) * ...  3 * 2 * 1
+  For example, 10! = 10 * 9 * ... * 3 * 2 * 1 = 3628800,
+  and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
+  Find the sum of the digits in the number 100!
+  
+solution: Bruteforce
+
+solutions:
+  solve.php:
+    desc: Basic solution
+    language: php
+  solve.rb:
+    desc: Basic solution
+    language: ruby

ProjectEuler/020/solve.php

@@ -0,0 +1,15 @@
+<?php
+define('FACTORIAL',100);
+
+function factorial($num) {
+	if($num == 0) 
+		return 1;
+	else 
+		return bcmul($num,factorial(bcsub($num,1)));
+}
+$sum = 0;
+$fac = factorial(FACTORIAL);
+for($c = 0; $c < strlen($fac); $c++) {
+	$sum += $fac[$c];
+}
+echo $sum;

ProjectEuler/020/solve.rb

@@ -0,0 +1,16 @@
+FACTORIAL = 100
+def factorial(num) 
+	if(num == 0) 
+		return 1
+	else 
+		return num * factorial(num - 1)
+	end
+end
+
+number = factorial(FACTORIAL)
+sum = 0
+
+number.to_s.each_char do |c|
+	sum += c.to_i
+end
+puts sum