C#实现的排列与组合(Permutation & Combination)算法

I wrote two generic class to implement these two algorithms, so you can use these classes to generate permutations and combinations for some use, such as software testing.

Using the Code:

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace CombinationAlgorithmic
{
    class Program
    {
        static void Main(string[] args)
        {
            ShowCombinations<int>(new int[] { 1, 2, 3, 4, 5 }, 3);
            ShowPermutations<string>(new string[] { "dog", "cat", "bird", "bat" }, 4);
        }

        static void ShowPermutations<T>(T[] array, int length)
        {
            Permutations<T> permutations = new Permutations<T>(array, length);
            Console.WriteLine("{0} Permutations of Array \"{1}\":\n", permutations.Count, GetString<T>(array));
            foreach (IList<T> perm in permutations)
            {
                Console.WriteLine(GetString<T>(perm) + "\n");
            }
        }

        static void ShowCombinations<T>(T[] array, int length)
        {
            Combinations<T> combinations = new Combinations<T>(array, length);
            Console.WriteLine("{0} Combinations of Array \"{1}\":\n", combinations.Count, GetString<T>(array));
            foreach (IList<T> oneCom in combinations)
            {
                Console.WriteLine(GetString<T>(oneCom) + "\n");
            }
        }

        static string GetString<T>(IList<T> list)
        {
            StringBuilder sb = new StringBuilder();
            foreach (T item in list)
            {
                sb.Append(item.ToString() + ",");
            }
            sb.Remove(sb.Length-1, 1);
            return sb.ToString();
        }
    }
}

output:

10 Combinations of Array "1,2,3,4,5":

1,2,3

1,2,4

1,2,5

1,3,4

1,3,5

1,4,5

2,3,4

2,3,5

2,4,5

3,4,5

24 Permutations of Array "dog,cat,bird,bat":

dog,cat,bird,bat

dog,cat,bat,bird

dog,bird,cat,bat

dog,bat,cat,bird

dog,bird,bat,cat

dog,bat,bird,cat

cat,dog,bird,bat

cat,dog,bat,bird

bird,dog,cat,bat

bat,dog,cat,bird

bird,dog,bat,cat

bat,dog,bird,cat

cat,bird,dog,bat

cat,bat,dog,bird

bird,cat,dog,bat

bat,cat,dog,bird

bird,bat,dog,cat

bat,bird,dog,cat

cat,bird,bat,dog

cat,bat,bird,dog

bird,cat,bat,dog

bat,cat,bird,dog

bird,bat,cat,dog

bat,bird,cat,dog

Download the Source Project:
https://files.cnblogs.com/Dah/PermutationCombination.rar

Note: If you find any bug or have some suggestion, please send E-Mail to me or leave your comments here, thanks!