Permutations of capitalization

Question

I want to build a list containing every possible permutation of capitalization of a word. so it would be

List permutate(string word)
{
    List         


        

Answer 1

Use bitwise operations. For a word of length N you need an integer type represented by N bits. If the word is longer - split it. Iterate through values from 0 to 2^N-1 and examine each bit from 0 to N-1. If the bit is 1 - upcase ( Char.ToUpper() ) the letter corresponding to that bit.

This approach is better that a recursive algorithm since it is not prone to stack overflows on long words.