What's the number

/*

Given a telephone number like 4156434531, get all possible names that would match it.

e.g. If the number is 23, the names could be "ad", "bd", "cd", "ae" etc..

*/

This non recursive implementation does not use a queue/stack to simulate recursion either.

namespace AlphaNumerics

{

public static class TelNumber

{

private static char[][] KeyChars = new char[10][];

static TelNumber()

{

KeyChars[0] = new char[]{'+'};

KeyChars[1] = new char[]{' '};

KeyChars[2] = new char[]{'a','b','c'};

KeyChars[3] = new char[]{'d','e','f'};

KeyChars[4] = new char[]{'g','h','i'};

}

public static void GetCombinations(int[] tel_no)

{

int[] digits = new int[tel_no.Length];

while(true)

{

Print(digits, tel_no);

if (!Increment(digits, tel_no)) break;

}

}

public static bool Increment(int[] digits, int[] tel_no)

{

int i = 0;

bool overflow = false;

for (; i < digits.Length; i++)

{

digits[i] = (digits[i] + 1) % KeyChars[tel_no[i]].Length;

if (digits[i] != 0) { overflow = false; break; }

else overflow = true;

}

return !overflow;

}

public static void Print(int[] digits, int[] tel_no)

{

for (int i = 0; i < tel_no.Length; i++)

{

System.Console.Write(KeyChars[tel_no[i]][digits[i]]);

}

System.Console.WriteLine();

}

}

}