Question

Write a program in the Codio programming environment that allows you to play the game of Rock / Paper / Scissors against the computer. Within the Codio starting project you will find starter code as well as tests to run at each stage. There are three stages to the program, as illustrated below. You must pass the tests at each stage before continuing in to the next stage.  We may rerun all tests within Codio before grading your program. Please see the executable version of the program within the Codio project for the definitive version of what it should look like, as sometimes conversion to html to display on this page can affect how the output lines up.

The first stage sets the computer guess to always be 'R' for Rock each move. Running the program with the first stage should look like the following:

CS 141 Program #1: Rock/Paper/Scissors

Welcome to the game of Rock/Paper/Scissors where you play against

the computer. On each move the computer will choose R, P, or S, then

the user will be prompted for their choice, and then the score will

be updated. P beats R, R beats S, and S beats P. The score starts

at 0. Add one if the person wins, subtract one if the computer wins.

The game ends if the score reaches -5 or + 5.

User input of 'x' or 'X' causes the game to exit.

Here we go!

Select how the computer chooses its move:

1. Always choose Rock

2. Random guess

3. Random guess with graphical score

Enter your choice: 1

1. Your move: r

   Computer chose R

   Tie. Score: 0

2. Your move: R

   Computer chose R

   Tie. Score: 0

3. Your move: p

   Computer chose R

   User's point. Score: 1

4. Your move: S

   Computer chose R

   Computer's point. Score: 0

5. Your move: x

Exiting program...

Tie game!

Ending program...     

The second stage uses a random number generator to set the computer's guess to be 'R' for Rock, 'P' for Paper, or 'S' for Scissors.  In order for your output to match what is expected, you must do the following:
1. Get a random number using rand() % 3 to give you a result of  0, 1, or 2

2. Use the result of the previous step to decide which letter to assign to the computer's guess. If it is 0, assign 'R'. If it is 1, assign 'P'. If it is 2, assign 'S'.
Running the second stage should look like the following:

CS 141 Program #1: Rock/Paper/Scissors

Welcome to the game of Rock/Paper/Scissors where you play against

the computer. On each move the computer will choose R, P, or S, then

the user will be prompted for their choice, and then the score will

be updated. P beats R, R beats S, and S beats P. The score starts

at 0. Add one if the person wins, subtract one if the computer wins.

The game ends if the score reaches -5 or + 5.

User input of 'x' or 'X' causes the game to exit.

Here we go!

Select how the computer chooses its move:

1. Always choose Rock

2. Random guess

3. Random guess with graphical score

Enter your choice: 2

1. Your move: r

   Computer chose P

   Computer's point. Score: -1

2. Your move: P

   Computer chose P

   Tie. Score: -1

3. Your move: r

   Computer chose R

   Tie. Score: -1

4. Your move: p

   Computer chose P

   Tie. Score: -1

5. Your move: x

Exiting program...

Computer wins!

Ending program...

The third stage is the same as the second except it displays the score graphically rather than as a number. Running the third stage should look like the following:

CS 141 Program #1: Rock/Paper/Scissors

Welcome to the game of Rock/Paper/Scissors where you play against

the computer. On each move the computer will choose R, P, or S, then

the user will be prompted for their choice, and then the score will

be updated. P beats R, R beats S, and S beats P. The score starts

at 0. Add one if the person wins, subtract one if the computer wins.

The game ends if the score reaches -5 or + 5.

User input of 'x' or 'X' causes the game to exit.

Here we go!

Select how the computer chooses its move:

1. Always choose Rock

2. Random guess

3. Random guess with graphical score

Enter your choice: 3

1. Your move: r

   Computer chose P

   Computer's point.

    -5 -4 -3 -2 -1 0 1 2 3 4 5

   ----------------------------------

   ..............^

2. Your move: s

   Computer chose P

   User's point.

    -5 -4 -3 -2 -1 0 1 2 3 4 5

   ----------------------------------

   .................^

3. Your move: p

   Computer chose R

   User's point.

    -5 -4 -3 -2 -1 0 1 2 3 4 5

   ----------------------------------

   ....................^

4. Your move: s

   Computer chose P

   User's point.

    -5 -4 -3 -2 -1 0 1 2 3 4 5

   ----------------------------------

   .......................^

5. Your move: x

Exiting program...

User wins!

Ending program...

What You Need to Know

• Environment:  How to use the codio.com environment to edit, compile and run a program.  
  On the codio.com starting page select the "Join Class" option at the upper-right. You will be prompted to enter a class token, which is: visa-compact Alternatively connect to the Codio course using this link
• Once you are in Codio, you should use the project called: Prog1: Rock-Paper-Scissors
  Within Codio project described above you can run the solution by doing the following:
  1. Select the Tools / Terminal menu option
  2. Within the terminal window, type in:  ./solution

• C++ Language concepts needed: simple input ( cin) and output (cout);  Using char and int variables; Incrementing a variable using ++; The assignment statement (=); How to compare variable values; Repeating a group of statements using a while loop; Choosing between alternatives using an if statement, including compound conditions; Using #include <cstdlib> so that the random number generator rand() works; Using the mod (%) operator; Breaking out of a loop using break;

Grading Rubric

The grading rubric is included in your starter code within your Codio project, and is included here as well.

55 Execution points

Option 1: (Computer always chooses R) and:

   2 User input of X immediately exits program

                3 User input of x (lower-case) immediately exits program

10 Program handles both lower and upper case user input (e.g. 'r' and 'R'); Move number increments each move

15 Score updates correctly for all user inputs: r, p, s

Option 2: Computer's move is random and:

   7 Predetermined input sequence correctly leads to a win for computer, with assessment results hidden

   8 Predetermined input sequence correctly leads to a win for computer, with assessment results hidden

      Option 3:

                  2        Correctly displays and updates the graphical score

   8       Correctly displays and updates the graphical score, with assessment results hidden

45 Programming Style (Given only if program runs substantially correctly)

10 Meaningful identifier names

10 Comments: Has header. Comments on each block of code.

15 Appropriate data and control structures. Code duplication is avoided.

10 Code Layout: Appropriate indentation and blank lines.

Answer 1

#include<iostream>
#include <string>   
#include <stdlib.h>
#include <time.h>
int getComputerChoice();
int getPlayerChoice();
bool isTie(int playerChoice,int computerChoice);
bool isPlayerWinner(int playerChoice,int computerChoice);
int main()
{
   char option;
   int computerChoice;
   int playerChoice;
   //srand funtion outside the loop
   //if we put inside the for loop same random number is generated
   //Srand will seed the random number generator to prevent random numbers from being the same every time
   srand(time(NULL));

   string computerSelection;
   string playerSelection;
  
   do
   {
       cout<<"ROCK PAPER SCISSORS MENU\n";
       cout<<"-------------------------\n";
       cout<<"p)Play Game\n";
       cout<<"q)Quit\n";
       cout<<"Enter your option\n";
       cin>>option;
       switch(option)
       {
           case 'p':
                   playerChoice =    getPlayerChoice();  
                   if(playerChoice==1)
                       cout<<"You chose: Rock\n";
                   else if(playerChoice==2)
                       cout<<"You chose: Paper\n";
                   else if(playerChoice==3)  
                       cout<<"You chose: Scissors\n";
                  
                   computerChoice = getComputerChoice();
                   if(computerChoice==1)
                       cout<<"The computer chose: Rock\n";
                   else if(computerChoice==2)
                       cout<<"The computer chose: Paper\n";
                   else if(computerChoice==3)  
                       cout<<"The computer chose: Scissors\n";
                      
                   if(isTie(playerChoice,computerChoice))  
                   {
                       cout<<"It's a TIE!\n";
                   }
                   else if(isPlayerWinner(playerChoice,computerChoice))
                   {
                       cout<<"You WIN!\n";
                   }
                   else
                   {
                       cout<<"Sorry you LOSE.\n";
                   }
                   break;
           case 'q':
                   break;
           default:
                   cout<<"Invalid Choice\n";      
       }
   }while(option!='q');
  

  
   return 0;
}

int getComputerChoice()
{
   int randnum;  
   //Generate number between 1 and 3
   randnum = 1 + (rand() % 3);
   return randnum;
}

int getPlayerChoice()
{
   int playerChoice;
   while(true)
   {
       cout<<"Rock, Paper or Scissors?\n";
       cout<<"1) Rock\n";
       cout<<"2) Paper\n";
       cout<<"3) Scissors\n";
       cout<<"Please enter your choice:\n";
       cin>>playerChoice;
       switch(playerChoice)
       {
           case 1:
               return 1;
               break;
           case 2:
               return 2;
               break;
           case 3:
               return 3;
               break;
           default:
               cout<<"Please enter 1 or 2 or 3 only\n";
       }
   }
   return playerChoice;
}

bool isTie(int playerChoice,int computerChoice)
{
   if(playerChoice==computerChoice)
       return true;
   else
       return false;
}

bool isPlayerWinner(int playerChoice,int computerChoice)
{  
   if(playerChoice==1 && computerChoice==3)
       return true;
   else if(playerChoice==3 && computerChoice==2)
       return true;
   else if(playerChoice==2 && computerChoice==1)
       return true;
   else  
       return false;
}