/****************************************************
Write a simple version of hangman, in which the user
enters the word he'll "guess", and then the user gets
to start guessing letters. After each guess, the word
is printed out with *s instead of unguessed letters.
 ****************************************************/
#include <iostream>
#include <string>

using namespace std;

// Prints each character of 'word',
// but if mask[i] is false, then the ith character
// prints an asterisk instead of the actual character.
// 'N' is the length of 'word' and the size of the mask array
void printMaskedWord(string word, bool *mask, int N);

// Check every letter of 'word'.
// If j'th letter of word is 'letter',
// then set j'th value of 'mask' to true
void updateMask(string word, bool *mask, int N, char letter);

// Returns true if every element of array 'mask' is true
bool checkWin(bool *mask, int N);

int main()
{
  // Get word to guess
  string word;
  cout << "Enter word to guess: ";
  cin >> word;

  // Set the mask array - mask[i] is true if the
  // character word[i] has been guessed.  The mask
  // must be allocated, and initialized to all false
  int N = word.length();
  bool *mask = new bool[N];
  for(int i = 0; i < N; i++)
    mask[i] = false;

  while (true) {
      // Print out word, showing letters guessed so far
      printMaskedWord(word, mask, N);

      // Get next letter     
      char letter;
      cout << "Enter letter: ";
      cin  >> letter;

      // Mark any letters that match
      updateMask(word, mask, N, letter);

      // Did they win?
      if (checkWin(mask, N)) 
      {
          printMaskedWord(word, mask, N);
          cout << "You win!";
          break;
      }
  }
  return 0;
}
  


// Prints each character of 'word',
// but if mask[i] is false, then the ith character
// prints an asterisk instead of the actual character.
// 'N' is the length of 'word' and the size of the mask array
void printMaskedWord(string word, bool *mask, int N) 
{
    for (int i=0; i<N;i++) 
    {
        if (mask[i])
        {
            // this letter has been guessed, so output it
            cout << word[i];
        }
        else
        {
            cout << "*";
        }
    }
    cout << endl;
}

// Check every letter of 'word'.
// If j'th letter of word is 'letter',
// then set j'th value of 'mask' to true
void updateMask(string word, bool *mask, int N, char letter)
{
    for (int i=0; i<N;i++)
    {
        if (word[i] == letter) 
        {
            // found match, so update mask
            mask[i] = true;
        }
    }
}


// Returns true if every element of array 'mask' is true
bool checkWin(bool *mask, int N) {
    bool win = true;
    for (int i=0;i<N;i++) 
    {
        if (mask[i] == false) 
        {
            win = false;
        }
    }
    return win;
}