using System.Collections;
using System.Collections.Generic;
private static Dictionary<int, string> dictNumbers = new Dictionary<int, string>()
{0, ""}, {1, ""}, {2, "abc"}, {3, "def"}, {4, "ghi"}, {5, "jkl"}, {6, "mno"}, {7, "pqrs"}, {8, "tuv"}, {9, "wxyz"}
public static void Main()
NumToWord(new int[]{2, 4});
private static void NumToWord(int[] nums)
printWordsUtil(nums, 0, new char[nums.Length], nums.Length);
private static void printWordsUtil(int[] number, int currentDigit, char[] output, int n)
string s = new string(output);
for (int i=0; i<dictNumbers[number[currentDigit]].Length; i++)
output[currentDigit] = dictNumbers[number[currentDigit]].ToCharArray()[i];
printWordsUtil(number, currentDigit+1, output, n);
if (number[currentDigit] == 0 || number[currentDigit] == 1)