Solved ProjectEuler/019: php, ruby

ProjectEuler/019/desc.yml

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+title: How many Sundays fell on the first of the month during the twentieth century?
+url: http://projecteuler.net/problem=19
+
+desc: |
+  You are given the following information, but you may prefer to do some research for yourself.
+  1 Jan 1900 was a Monday.
+  Thirty days has September,
+  April, June and November.
+  All the rest have thirty-one,
+  Saving February alone,
+  Which has twenty-eight, rain or shine.
+  And on leap years, twenty-nine.
+  A leap year occurs on any year evenly divisible by 4, but not on a century unless it is divisible by 400.
+  How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)?
+
+  
+solution: Instead of using buildtin DateTime language features this use a homemade algorithm
+
+solutions:
+  solve.php:
+    desc: Basic solution
+    language: php
+  solve.rb:
+    desc: Basic solution
+    language: ruby

ProjectEuler/019/solve.php

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+<?php
+$days_in_month = array( 
+	1 => 31,
+	2 => 28,
+	3 => 31,
+	4 => 30,
+	5 => 31,
+	6 => 30,
+	7 => 31,
+	8 => 31,
+	9 => 30,
+	10 => 31,
+	11 => 30,
+	12 => 31
+);
+$day_cycle = 0;
+for($year=1900; $year <= 2000; $year++) {
+	for($month=1; $month <= 12; $month++) {
+	
+		$cdates = $days_in_month[$month];
+			if($month == 2) {
+			if($year % 4 == 0) {
+				$cdates = 29;
+			}
+			if($years % 100 == 0) {
+				$cdates = 28;
+			}
+			if($years % 400 == 0) {
+				$cdates = 29;
+			}
+			}
+			$day_cycle += $cdates;
+			if($day_cycle % 7 == 0) {
+				if($year >= 1901) {$sum++; }
+			}
+	}
+}
+echo $sum;

ProjectEuler/019/solve.rb

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+require "date"
+sundays = 0
+(1901..2000).each do |year|
+	(1..12).each do |month|
+			dt = Date.new(year,month,1)
+			sundays += (dt.wday == 0) ? 1 : 0
+	end
+end
+puts sundays