Check letters against the word of an arbitrary size in a Hangman game

Question

Currently I am working on a hangman game, I had previously coded it to only work for a 5 letter word, but now would like to make it handle any length of word, how could I change this code to make it work how I want it to?

#include "stdafx.h"
#include <iostream>
#include <string>
#include <stdlib.h>
#include <cstdlib>
using namespace std;

int main()
{
string word;
int tries;
string guess;
string wordguess;
string output;

cout << "Enter a word for player two to guess: ";
cin >> word;
system("CLS");
cout.flush();
cout << "Guess the word!" << endl;

for (int i = 0; i < word.length(); i++)
{
cout << "_ ";
}

cout << "Enter a letter: ";
cin >> guess;

for (int tries = 5; tries > 0; tries--)
{
if (guess[0] == word[0]) {
    output[0] = word[0];
    cout << "You guessed the first letter! Good job!" << endl;
}
if (guess[0] == word[1]) {
    output[2] = word[1];
    cout << "You guessed the second letter! Good job!" << endl;
}
if (guess[0] == word[2]) {
    output[4] = word[2];
    cout << "You guessed the third letter! Good job!" << endl;
}
if (guess[0] == word[3]) {
    output[6] = word[3];

    cout << "You guessed the fourth letter! Good job!" << endl;
}
if (guess[0] == word[4]) {
    output[8] = word[4];
    cout << "You guessed the fifth letter! Good job!" << endl;
}

cout << output << endl;
cout << "You have " << tries << " tries left. Take a guess at the word: " << endl;
cin >> wordguess;
if (wordguess == word)
{
    cout << "Congratulations, you guessed the word correctly!" << endl;
    break;
}
}
    system("pause");
    return 0;
}

As you can tell I was checking each position from 0 to 4 (first through fifth letter). I know there are plenty of ways that I could have coded this better but as you can guess, I am new to coding and this is the way I thought of it. Please note this is still a work in progress so it is not fully complete. Any help would be great!

Answer 1

When designing an algorithm, think of how you would do this by hand, without a computer. Then let the code do the same.

If you were checking your friend's guess against a word written on sand, you would probably go about it like this:

• go through the written pattern character by character, pronouncing your word in memory
• for each letter, check if it is equal to the guess

• if it is

  • replace the placeholder with it
  • memorize that your friend guessed right.
  • Also note if there are any placeholders left
    • if there aren't, your friend wins

• finally, if your friend didn't guess right, score them a penalty point and check if they lose

Now, all that leaves is to put this down in C++. The language provides all sorts of entities - let's check which ones fit ours needs the best:

• the word and the current pattern - strings of a fixed size

• bits to memorize:

  • whether the current guess is right - bool
  • placeholders left - int
  • penalty points (or, equivalently, attempts left) - int

• parts of the algorithm:

  • looping over a string - for loop of one of a few kinds
    • we need to replace the character in the pattern at the same index as the guessed letter in the word. So, we need to have the index when looping. Thus the flavor with the index variable, for(std::string::size_type i = 0; i < str.size(); ++i) probably fits the best.

Answer 2

// Example program
#include <iostream>
#include <string>
using namespace std;

class my_game
{
private:
    string congrats_array[15] = {"first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "nineth", "tenth", "eleventh", "twelfth", "thirteenth", "fourteenth", "fifteenth"};
    string word_to_guess;
    int tries_left;
    int word_length;
    int letters_guessed_count;
    string guessed_letters;

    void check_letter(char letter); 
    void print_current_word_state();

public:
    my_game();
    void begin_the_game();
    void play_the_game();   
};

my_game::my_game()
{

}

void my_game::begin_the_game()
{
    cout << "Enter a word for player to guess: " << endl;
    cin >> word_to_guess;
    system("CLS");
    cout.flush();

    cout << "Enter the tries amount!\n" << endl;
    cin >> tries_left;

    word_length = word_to_guess.size();

    guessed_letters = "_";
    letters_guessed_count = 0;

    for(int i = 0; i < word_length - 1; i++){
        guessed_letters += "_";   
    }
}

void my_game::play_the_game()
{
    cout << "Guess the word!" << endl;
    char letter;

    for(int i = 0; i < tries_left; i++)
    {
        cout << guessed_letters << endl;
        cout << "Enter a letter: " << endl;
        cin >> letter;
        check_letter(letter);

        if(letters_guessed_count == word_length){
            cout << "Congrats! You won!" << endl;
            return;
        }
    }

    cout << "You lose" << endl;
}

void my_game::check_letter(char letter)
{
    for(int i = 0; i < word_length; i++)
    {
        if(word_to_guess[i] == letter && guessed_letters[i] != letter)
        {
            guessed_letters[i] = letter;
            letters_guessed_count++;
            cout << "You guessed the" << congrats_array[i] <<"letter! Good job!" << endl;
        }
    }
}


int main()
{
  my_game game;
  game.begin_the_game();
  game.play_the_game();
}

Answer 3

So, in short what you need to do this with words of any arbitrary length is to use string's .substr() function and the stringstream library's .str() and << and >> operators. This version of your code uses a function that inserts a correctly guessed character at the appropriate indexed location. This will gradually replace the "_________" with letters at the correct places. This is much easier to do in Java, but stringstream is a good library I would highly recommend getting familiar with it. I'll leave the problem of how to handle multiple instances of a guessed character up to you (ie 'i' in "bibliography")

#include <string>
using std::string;

#include <sstream>
using std::stringstream;

#include <iostream>
using std::cout;
using std::cin;
using std::endl;

string newString(string, int, string);

int main()
{
    string word;
    string guess;
    int tries;
    string output;

    string input;

    cout << "Enter word for player 2 to guess: "; 
    cin >> word;

    stringstream ss;

    //---------- fills the stream with "_"s matching the length of word

    for(int i = 0; i < word.length(); i++)
        ss << "_";

    //----------- assigns the initial value of "___..." to output

    ss >> output;

    //----------- sets up the loop 

    tries = 5; 
    bool found = false;

    for(int i = 0; i < 5; i++)
    {
        cout << "\nTry " << i << " of 5: Enter a letter or guess the word: "; 
        cin >> input;

        if(input == word)
        {
            cout << "Congratulations, you guessed the word correctly!" << endl;
            break;
        }

        //------------------ else, proceed with replacing letters 

        if(word.find(input) != std::string::npos)
        {
            size_t position = word.find(input);                                         // finds index of first instance of the guessed letter
            cout << "You guessed the " << position+1 << " letter! Good job!" << endl;   // since strings start at index 0, position+1

            //------- replaces appropriate "_" with the guessed letter

            output = newString(input, position, output);
            cout << "\n" << output;

             // Around here you'll want to set up a way to deal with multiple instances 
             // of the same letter

        }
        else
            cout << "Incorrect guess" << endl; 
    }

    return 0;
}

//---------------------------------------------------

string newString(string guess, int index, string word)
{
    string NewString;
    stringstream temp;

    //---------- hack up the string into sections before and after the index

    string before = word.substr(0, index);
    string after = word.substr(index+1, word.length() - index+1);

    //---------------- populates the new stringstream and assigns it to the result

    temp << before << guess << after;

    NewString = temp.str();

    return NewString;
}