Question

C++ :

Proj...

Make sure to have at least this three functions:

double median(int *, int);

int mode(int *, int);

double average(int *, int);

Expected output is shown below with input validation.

How many students were surveyed? -9

The number of students must be greater than zero.

How many students were surveyed? 5

Enter the number of movies each student saw.

Student 1: -5

The number of movies must be greater than zero.

How many movies were seen by Student 1? 6

Student 2: 7

Student 3: 8

Student 4: 9

Student 5: 9

The average number of movies seen is 7.8.

The median of the number of movies seen is 8.

The mode of the number of movies seen is 9.

Answer 1

Solution:

#include<iostream>       //Including header files..
#include<string>

using namespace std;

double median(int *, int);       //Declaring functions..
int mode(int *, int);          
double average(int *, int);
int getInput();              

int main() {
  
   int END = 1;       //Conditional variable..
   int studentsCount;    //To store no.of students were surveyed
    int studentsWatched[100];//To store no.of movies each student saw..  
   int i = 0;
   double med;           //Declaring variables..  
   double mod;
   double avg;

   while (END) {       //Loop to get valid input..

       cout <<"\n How many students were surveyed? ";
       studentsCount = getInput();       //Function call to read input..  
       if (studentsCount != -1) {
           cout <<"\n Enter the number of movies each student saw.\n";
           for (i = 1; i <= studentsCount; i++)   //Index start at '1'..
           {
                 cout <<" Student "<<i<<": ";
               studentsWatched[i]= getInput(); //Function call to read input.

               if (studentsWatched[i] == -1)       //Invalid input..
               {              
                      i--; //Repeat prompting the value from uesr..
                       cout<<" The number of movies must be greater than zero.";
                      cout <<"\n How many movies were seen by";
               }
           }

           med = median(studentsWatched, studentsCount);   //Func call to find median..
           mod = mode(studentsWatched,studentsCount);       //Func call to find mode..
           avg = average(studentsWatched, studentsCount);       //Func call to find average..
      
           //Printing output...
           cout<<" The average number of movies seen is "<<avg;
           cout<<".\n The median of the number of movies seen is "<<med;
           cout<<".\n The mode of the number of movies seen is "<<mod<<".\n"<<endl;

           END = 0;   //Exit program..
       }
       else
            cout<<" The number of students must be greater than zero.";
           continue; //Start from first..
   }
   return 0;
}
/*
* Function to find the median..
*/
double median(int *studentsWatched, int studentsCount)
{
   int middle = (studentsCount/2)+1;
   double median = 0;              
   if (studentsCount % 2 == 1)
        median = *(studentsWatched + middle);
   else
        median = (double)((*(studentsWatched + middle-1) + *(studentsWatched + middle)) / 2);

   return (double)median;
}
/*
* Function to find the mode..
*/
int mode(int *studentsWatched, int studentsCount)
{
   int mod = *(studentsWatched + 1); //Assigning first element..
   int result = mod;                  //To store the result..
   int count = 1;                   //To store the count..
   int modCount = 1;               //To store the modCount..

   for (int i = 2; i <= studentsCount+1; i++)
   {
       if (*(studentsWatched + i) == mod) {
           count++;       //Increase count value..
       }
       else {
           if (count > modCount)
           {
               modCount = count; //Storing the highest count
               result = mod;      //Storing the highest count's index
           }
           count = 1;        // Reset the value of count next nos..
           mod = *(studentsWatched + i); //Assigning next element..
       }
   }

   return result;
}
/*
* Function to find the average..
*/
double average(int *studentsWatched, int studentsCount)
{
   int sum = 0;       //To store the sum of array elements..
   for (int i = 1; i <= studentsCount; i++)
              sum += *(studentsWatched + i); //Calculating sum  

   return (double)sum/studentsCount;   //Calculating average & return..
}
/*To read the input from the user..*/

int getInput()
{
   int input;
   cin>> input;
   if(input > 0)  
       return input;   //Return if valid input..
   else
      return -1;       //If invalid input..
}   

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Code Screenshots:

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Output:

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