Unique Combinations

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

• C#
• VB.Net
• C
• C++
• PHP

									public static List<List<string>> GenerateCombinations(string[] arr)
{
	List<List<string>> combinations = new List<List<string>>();
	int length = arr.Length;

	for (int i = 0; i < (1 << length); ++i)
	{
		List<string> combination = new List<string>();
		int count = 0;

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

		if (count > 0 && combination.Count > 0)
			combinations.Add(combination);
	}

	return combinations;
}
								

Example

									string[] arr = { "How", "Are", "You" };
List<List<string>> combinations = GenerateCombinations(arr);
								

Output

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