Unique Combinations

This algorithm finds all unique combinations in a specified list of values.

• C#
• VB.Net
• C
• C++
• PHP

									function GenerateCombinations($arr)
{
	$combinations = array();
	$length = count($arr);

	for ($i = 0; $i < (1 << $length); ++$i)
	{
		$combination = array();
		$count = 0;

		for ($count = 0; $count < $length; ++$count)
		{
			if (($i & 1 << $count) > 0)
				$combination[] = $arr[$count];
		}

		if ($count > 0 && count($combination) > 0)
			$combinations[] = $combination;
	}

	return $combinations;
}
								

Example

									$arr = array("How", "Are", "You");
$combinations = GenerateCombinations($arr);
								

Output

									{"How"}
{"Are"}
{"How", "Are"}
{"You"}
{"How", "You"}
{"Are", "You"}
{"How", "Are", "You"}