Create JumpSearch.php

Searches/JumpSearch.php

@@ -0,0 +1,50 @@
+<?php
+/**
+   * Jump Search algorithm in PHP
+   * References: https://www.geeksforgeeks.org/jump-search/
+   * The list must be sorted in ascending order before performing jumpSearch
+   *
+   * @param Array $list refers to a sorted list of integer 
+   * @param integer $key refers to the integer target to be searched from the sorted list
+   * @return index of $key if found, otherwise -1 is returned
+ */
+   
+function jumpSearch($list,$key)
+{
+	/*number of elements in the sorted array*/
+	$num = count($list);
+	/*block size to be jumped*/
+	$step = (int)sqrt($num);
+	$prev = 0;
+	
+	while ($list[min($step, $num)-1] < $key)
+	{
+		$prev = $step;
+		$step += (int)sqrt($num);
+		if ($prev >= $num)
+			return -1;
+	}
+
+	/*Performing linear search for $key in block*/
+	while ($list[$prev] < $key)
+	{
+		$prev++;
+		if ($prev == min($step, $num))
+			return -1;
+	}
+	
+     return $list[$prev] === $key ? $prev : -1;
+}
+
+
+/* 
+ *Test jumpSearch
+ */
+$list = array( 3,5,6,7,9,10,12,20,22,24 );
+$key=12;
+
+/*Print out index of $key in the sorted list*/
+echo "The index of ".$key." is ".jumpSearch($list,$key);
+return 0;
+
+?>