Question

A professor wants to do some research on students who use different kinds of computers. They are curious if there is any difference in average test scores between , for instance, Mac users and Windows users. Write a program to help with this, that behaves as follows.

• The user repeatedly enters a computer type, picking Mac, Windows or Other by entering "m", "w", or "o", along with a test score from 0 to 100. The user enters "x" to indicate they are done inputting data.
• The program will calculate the average test score for each computer type separately.
  • Note that this means you need 3 separate counters and 3 separate accumulators, one for each computer type. Each time a computer type and score is entered, you need to update the appropriate accumulator and counter. A switch would be very useful here!
• When all input is complete, calculate and display the average test score for each computer type, with one decimal place.
• If there are no students for a particular computer type, instead of outputting an average test score, only output "No Windows users", "No Mac users" or "No Other users".
• Your program must work for upper or lowercase. In other words, all of these are valid inputs for computer type: "M", "m", "W", "w", "O", "o", "X", "x". This is easiest to do with a String variable and a switch statement with cases "stacked" on top of each other, or convert the string to upper or lower case before starting the switch.

Answer 1

Here is the code, I have tried to be as descriptive as possible :

#include <bits/stdc++.h>

using namespace std;

float sumW = 0, sumO = 0, sumM = 0;                // These values are the accumulators for each type of computer.
int countW = 0, countO = 0, countM = 0;         // These values the counters for each accumulator.

int main()
{
   while(1){                                                       // This will run until x or X is entered as an input.
       cout<<" Enter the type of computer or enter x/X to compute the scores : ";
       char choice;
       cin>>choice;
      
       int score;
       switch(choice)                                      // in each case we increment the values of the accumulator
       {                                                           // and the counter. except the x case in that , we print
           case 'm':                                          // the averages of the score or print no user if no entry of
           case 'M':                                          // that type is made.
               cout<<" Enter the score : ";
               cin>>score;
               sumM += score;
               countM++;
               break;
              
            case 'w':
            case 'W':
               cout<<" Enter the score : ";
               cin>>score;
               sumW += score;
               countW++;
               break;
              
           case 'o':
           case 'O':
               cout<<" Enter the score : ";
               cin>>score;
               sumO += score;
               countO++;
               break;
              
           case 'x':
           case 'X':
               if(sumM==0){
                   cout<<"No Mac Users.\n";
                   }
               else{
                   printf("The average test score for mac users is : %.1f\n", sumM/countM);
                   }
               if(sumW==0){
                   cout<<"No Windows Users.\n";
                   }
               else{
                   printf("The average test score for windows users is : %.1f\n", sumW/countW);
                   }
               if(sumO==0){
                   cout<<"No Other Users.\n";
                   }
               else{
                   printf("The average test score for other users is : %.1f\n", sumO/countO);
                   }
               exit(0);
               break;
           default:
           break;
       }
   }
    return 0;
}