Question

(c++ only)Write a program that lets the user play the game of Rock, Paper, Scissors against the computer. The program should work as follows:

1. When the program begins, the user enters his or her choice of “rock”, “paper”, or “scissors” at the keyboard using a menu in a function, userChoice, that returns a character.

2. Next, there should be a function, computerChoice, that generates the computer’s play. A random number in the range of 1 through 3 is generated. If the number is 1, then the computer has chosen rock. If the number is 2, then the computer has chosen paper. If the number is 3, then the computer has chosen scissors. The computer’s choice is returned as a character.

3. After, a function, determineWinner, will determine the winner between the user’s choice vs. the computer’s choice. (NOTE: It will return nothing, but it will take in the user’s choice and the computer’s choice as the two arguments.) The result is selected according to the following rules:

   1. If one player chooses rock and the other player chooses scissors, then rock wins. (The rock smashes the scissors.)

   2. If one player chooses scissors and the other player chooses paper, then scissors wins. (Scissors cuts paper.)

   3. If one player chooses paper and the other player chooses rock, then paper wins. (Paper wraps rock.)

   4. If both players make the same choice, the game ends in a draw and there is no winner.

4. Finally, after a result is selected, there should be a function, playAgain, in which the player should have the option of playing again. This should return a boolean.

Be sure that the program contains at least the four functions mentioned in parts a – d.

Answer 1

Here is the code that I have implemented.

Source code:

#include<iostream>
#include<ctype.h>
#include <stdlib.h>
using namespace std;
char userChoice(){
char choice;
cout<<"Welcome to Rock/Paper/Scissors Game! Here are your choices.\n";
cout<<"(R/r)  Rock\n(P/p)  Paper\n(S/s)  Scissors\n";
cin>>choice;
if(choice!='R' && choice!='r' && choice!='P' && choice!='p' && choice!='S' && choice!='s' && choice!='Q' && choice!='q'){
    cout<<"Invalid Choice.Please try again!!\n";
    userChoice();
}
return choice;
}
char computerChoice(){
/*
Here rand will generate number from 0 to RAND_MAX
but we modulo it to get number in range 1-3
*/
int randchoice=((rand()%3)+1);
char choice;
switch(randchoice){
case 1:
    choice='R';
    break;
case 2:
    choice='P';
    break;
case 3:
    choice='S';
    break;
}
return choice;
}
void determineWinner(char usrchoice,char compchoice){
//Rock v\s scissors Rock wins
if((usrchoice=='R' || usrchoice=='r') && (compchoice=='S' || compchoice=='s')){
        cout<<"User wins\n";
   
        return;
}
else if((usrchoice=='S' || usrchoice=='s') && (compchoice=='R' || compchoice=='r')){
    cout<<"Computer wins\n";
    return;
}
//scissors v\s paper scissors wins
else if((usrchoice=='S' || usrchoice=='s') && (compchoice=='P' || compchoice=='p')){
        cout<<"User wins\n";
        return;
}
else if((usrchoice=='P' || usrchoice=='p') && (compchoice=='S' || compchoice=='s')){
    cout<<"Computer wins\n";
    return;
}
//paper v\s rock paper wins
else if((usrchoice=='P' || usrchoice=='p') && (compchoice=='R' || compchoice=='r')){
    cout<<"User wins\n";
    return;
}
else if((usrchoice=='R' || usrchoice=='r') && (compchoice=='P' || compchoice=='p')){
    cout<<"Computer wins\n";
    return;
}
//Both have same choice game draws
else if(tolower(usrchoice)==tolower(compchoice)){
    cout<<"There is no winner.Game draw\n";
    return;
}
}
bool playagain(){
bool b;
char ch;
cout<<"Do you want to play again (Y/y) for yes (N/n) for no)?";
cin>>ch;

if(ch=='Y' || ch=='y')
    b=true;
else if(ch=='N' || ch=='n')
    b=false;
 else{ 
     cout<<"Invalid Option.Please try again!!!\n";
     b=playagain();
 }
  return b;
}
void showChoices(char usrchoice,char cmpchoice){
string usr,cmp;
//user choice
    if(usrchoice=='R' || usrchoice=='r'){
        usr="Rock";
    }
    else if(usrchoice=='P' || usrchoice=='p'){
        usr="Paper";
    }
    else{
        usr="Scissors";
    }
    //computer choice
    if(cmpchoice=='R' || cmpchoice=='r'){
        cmp="Rock";
    }
    else if(cmpchoice=='P' || cmpchoice=='p'){
        cmp="Paper";
    }
    else{
        cmp="Scissors";
    }
    cout<<"Your choice: "<<usr<<endl;
    cout<<"Computer Choice: "<<cmp<<endl;
}
int main(){
while(true){
    char usrchoice=userChoice();
    char compchoice=computerChoice();
    showChoices(usrchoice,compchoice);
    determineWinner(usrchoice,compchoice);
    bool b=playagain();
    // In case b is true we play again else we terminate
    if(b)
        continue;
    else{
        cout<<"Thank you for Playing Rock/Paper/Scissors\n";
        break;
    }
}

}

Output:

Feel free to reach out to me in comment in case you have any doubt or need any clarifications. I will be more than happy to help.

Welcome to Rock/Paper/Scissors Game! Here are your choices. (R/r) Rock (P/p) Paper (S/3) Scissors Your choice: Rock Computer Choice: Paper Computer wins Do you want to play again (Y/y) for yes (N/n) for no)?y Welcome to Rock/Paper/Scissors Game! Here are your choices. (R/r) Rock (P/p) Paper (S/s) Scissors Your choice: Paper Computer Choice: Paper There is no winner.Game draw Do you want to play again (Y/y) for yes (N/n) for no) ?n Thank you for Playing Rock/Paper/Scissors ...Program finished with exit code O Press ENTER to exit console. I