two simple functions to change hex cipher into decimal number and backwords

hex-encoding.cpp

char decToHex(int n){
    if(n<15||n>0){
      switch(n){
        case 10:
        return 'a';
        case 11:
        return 'b';
        case 12:
        return 'c';
        case 13:
        return 'd';
        case 14:
        return 'e';
        case 15:
        return 'f';
      }
      return ('0'+n);
    }
    return -1;
  }
  int hexToDec(char n){
    switch(n){
      case '0':
      return 0;
      case '1':
      return 1;
      case '2':
      return 2;
      case '3':
      return 3;
      case '4':
      return 4;
      case '5':
      return 5;
      case '6':
      return 6;
      case '7':
      return 7;
      case '8':
      return 8;
      case '9':
      return 9;
      case 'a':
      return 10;
      case 'b':
      return 11;
      case 'c':
      return 12;
      case 'd':
      return 13;
      case 'e':
      return 14;
      case 'f':
      return 15;
    }
    return -1;
  }