Solved ProjectEuler/019: php, ruby

ProjectEuler/019/solve.php

@@ -0,0 +1,38 @@
+<?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;