Card Guessing

Card Guessing Game

Video Summary: https://youtu.be/rUoYh0XA4MI

In this exercise, you will create the greater than/less than card guessing game. In this game, a card is drawn, and the player guesses whether the next card will be greater than or less than that card. You can start from this solution to a previous exercise:

/*
file name: drawcard.cpp
author: Devon Blewett
purpose: This program generates a random number between 1 and 13 and places it in a box to represent a card.  It also selects a suit and places the symbol in the top left and bottom right corners.

Written for the Open Textbooks program
*/

#include <iostream>
#include <iomanip>
#include <time.h>

using namespace std;

int main() {
    
    // draw a card between 1 and 13
    srand(time(NULL));
    int card = rand() % 13 + 1;
  
    // enumerator datatype for the card suit
    enum suit {diamonds, hearts, clubs, spades};
    
    // draw a suit between 0 and 3
    suit currentSuit = suit(rand() % 4);
    // string variable to hold symbol
    string symbol;
     
    // switch to assign symbol to string
    switch(currentSuit){
        case diamonds:
            symbol = "♦";
            break;
        case hearts:
            symbol = "♥";
            break;
        case clubs:
            symbol = "♣";
            break;
        case spades:
            symbol = "♠";
            break;
        default:
            symbol = "";
    }
    
    // create the top line of dashes
    cout << setfill('-') << setw(7) << "" << endl;
    // create 2nd row, empty
    cout << "|" << symbol << setfill(' ') << setw(5) << "|" << endl;
    // put number in third row, left aligned to prevent card from breaking if double digit card drawn
    cout << "|  " << setw(2) << left << card  << " |" << endl;
    // create 4th row, reset align to right
    // space was added to setw here to accomodate using unicode symbol
    cout << "|" << right << setw(7) << symbol << "|" << endl;
    // create bottom row of dashes
    cout << setfill('-') << setw(7) << "" << endl;
    
    return 0;
}

First, divide the features of the program into different functions:

A function to generate a random number
A function for the switch statement to assign the symbol
A function to draw the card

After this:

Create a function that will prompt the user to guess greater than or less than. You could use the symbols '<' and '>'
Create a function to evaluate if the user guessed correctly
Create a loop to keep drawing and guessing cards

You may loop the game infinitely or ask the user if they want to keep playing. When you are finished, your output might look like this:

-------
|♠    |
|  7  |
|    ♠|
-------
Will the next card be greater or less than this card?  Enter '<' or '>'<
-------
|♦    |
|  9  |
|    ♦|
-------
Your guess is incorrect
Will the next card be greater or less than this card?  Enter '<' or '>'<
-------
|♦    |
|  5  |
|    ♦|
-------
Your guess is correct
Will the next card be greater or less than this card?  Enter '<' or '>'>
-------
|♠    |
|  11 |
|    ♠|
-------
Your guess is correct
Will the next card be greater or less than this card?  Enter '<' or '>'
signal: terminated

Some hints:

You could use the same function to generate the card and suit if you pass the int you want to use modulus with. This function would return int, and you would need to add 1 for the card value.
The function to evaluate if the user is correct or not could either return a string result or be a void that prints the result within the function
The function prompting input will either need a string return, or have the string passed by reference to store the user's answer
You will need variables for two card numbers - the card the user saw first, and the second card they bet on. At the end of the loop, update the previous card to the new card
You will need to declare the enum for the suit globally if you want to pass an enum datatype

Solution

/*
file name: guesscard.cpp
author: Devon Blewett
purpose: This program generates a random number and suit for a card, displays it, then prompts the user to guess if the next card drawn will be greater or less than the current one.

The game infinitely loops until the user presses stop or hits ctrl + c

Written for the Open Textbooks program
*/

#include <iostream>
#include <iomanip>
#include <time.h>

using namespace std;
// enumerator datatype for the card suit.  Needs to be moved here for function prototype
enum suit {diamonds, hearts, clubs, spades};
// function prototypes
int getRandom(int n);
string getSuitSymbol(suit currentSuit);
void drawCard(int card, string symbol);
string guessPrompt();
void checkResult(int oldCard, int newCard, string guess);

int main() {
    
    // draw a card between 1 and 13
    srand(time(NULL));
    int card = getRandom(13) + 1;
    
    // draw a suit between 0 and 3
    suit currentSuit = suit(getRandom(4));
    // string variable to hold symbol
    string symbol = getSuitSymbol(currentSuit);
    // call function to draw the card
    drawCard(card, symbol);

// start game loop
    while(true){
    // call function to prompt user
    string guess = guessPrompt();
    // generate the next card
    int newCard = getRandom(13) + 1;
    suit newSuit = suit(getRandom(4));
    string newSymbol = getSuitSymbol(newSuit);
    drawCard(newCard, newSymbol);
    // check the user's guess against the new card
    checkResult(card, newCard, guess);
    // update the stored card so the user can guess again
    card = newCard;
    }
    return 0;
}
/*
function name: getRandom
parameters: integer n to determine limit
purpose: Generates a random number between 0 and n
*/
int getRandom(int n){
    return rand() % n;
}
/*
function name: getSuitSymbol
parameters: enum suit currentSuit - used for the switch to determine what symbol to select
purpose: Return a string that matches the suit that was randomly selected
*/
string getSuitSymbol(suit currentSuit){
    string symbol;
        // switch to assign symbol to string
    switch(currentSuit){
        case diamonds:
            symbol = "♦";
            break;
        case hearts:
            symbol = "♥";
            break;
        case clubs:
            symbol = "♣";
            break;
        case spades:
            symbol = "♠";
            break;
        default:
            symbol = "";
    }
    return symbol;
}
/*
function name: drawCard
parameters: int card - value of the card
            string symbol - symbol for the suit of the card
purpose: Draw a card-like box with the value in the middle and symbol in the top left and bottom right corner
*/
void drawCard(int card, string symbol){
     // create the top line of dashes
    cout << setfill('-') << setw(7) << "" << endl;
    // create 2nd row, empty
    cout << "|" << symbol << setfill(' ') << setw(5) << "|" << endl;
    // put number in third row, left aligned to prevent card from breaking if double digit card drawn
    cout << "|  " << setw(2) << left << card  << " |" << endl;
    // create 4th row, reset align to right
    // space was added to setw here to accomodate using unicode symbol
    cout << "|" << right << setw(7) << symbol << "|" << endl;
    // create bottom row of dashes
    cout << setfill('-') << setw(7) << "" << endl;
}
/*
function name: guessPrompt
parameters: None
purpose: Prompt the user to guess less than or greater than and return the result
*/
string guessPrompt(){
    string guess;
    while(guess != ">" && guess != "<"){
    cout << "Will the next card be greater or less than this card?  Enter '<' or '>'";
    cin >> guess;
        }
    return guess;
}
/*
function name: checkResult
parameters: int oldCard - the value of the first card drawn
            int newCard - the value of the second card drawn
            string guess - the user's guess of greater or less  than
purpose: Compare the value of the two cards that were drawn, and decide if the user guessed correctly if the second card was greater than or less than.  Prints result to console
*/
void checkResult(int oldCard, int newCard, string guess){
    if(oldCard<newCard){
        if(guess == ">"){
            cout << "Your guess is correct" << endl;
        }
        else{
            cout << "Your guess is incorrect" << endl;
        }
    }
    else if(oldCard>newCard){
        if(guess==">"){
            cout << "Your guess is incorrect" << endl;
        }
        else{
            cout << "Your guess is correct" << endl;
        }
    }
    else{
        cout << "The cards are equal" << endl;
    }
}

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