Generate Permutation and Combinations of a given string

Attached an improved version where you can pass more than 3 words (and it will work).

Also possible to tell which permutation level you want


Testing is included see
        private void Form1_Load(object sender, EventArgs e)
        {
            List<string> combination = CombinateWords(new[] { "bat","cow","dog","mouse" },null);

            List<string> permutations = new List<string>();
           
            foreach (string combinatedString in combination)
            {
                permutations.AddRange(PermuteWords(combinatedString));

            }

            List<string> permutLevel = CombinationPermutation(new[] {"bat", "cow", "dog", "mouse"}, 2);
        }
EE.txt

Thanks a lot Dhaest and Idle_Mind for your quick and valuable inputs.
I will revert after testing your suggested codes.

Thanks
Ajay Sharma

I didn't got time to apply your codes but one of my Google search gave me this famous PermuteUtils link. It worked great for me after modifying a bit.

Thanks all for your time, efforts and help.

Thanks