Question

I’m trying to create an algorithm in C# which produces the following output strings:

AAAA AAAB AAAC ...and so on... ZZZX ZZZY ZZZZ 

What is the best way to accomplish this?

public static IEnumerable<string> GetWords() {     //Perform algorithm     yield return word; } 

Answer 1

well, if the length is a constant 4, then this would handle it:

public static IEnumerable<String> GetWords() {     for (Char c1 = 'A'; c1 <= 'Z'; c1++)     {         for (Char c2 = 'A'; c2 <= 'Z'; c2++)         {             for (Char c3 = 'A'; c3 <= 'Z'; c3++)             {                 for (Char c4 = 'A'; c4 <= 'Z'; c4++)                 {                     yield return '' + c1 + c2 + c3 + c4;                 }             }         }     } } 

if the length is a parameter, this recursive solution would handle it:

public static IEnumerable<String> GetWords(Int32 length) {     if (length <= 0)         yield break;      for (Char c = 'A'; c <= 'Z'; c++)     {         if (length > 1)         {             foreach (String restWord in GetWords(length - 1))                 yield return c + restWord;         }         else             yield return '' + c;     } }