Question

You are to write three functions for this lab: mean, remove, display. Download the main.cpp file provided to get started.

Read the comments in the main function to determine exactly what the main function should do.

//include any standard libraries needed

// - Passes in an array along with the size of the array.
// - Returns the mean of all values stored in the array.
double mean(const double array[], int arraySize);

// - Passes in an array, the size of the array by reference, and the index of a value to be removed from the array.
// - Removes the value at this index by shifting all of the values after this value up, keeping the same relative order of all values not removed.
// - Reduces arraySize by 1.
void remove(double array[], int &arraySize, int index);

// - Passes in an array and the size of the array.
// - Outputs each value in the array separated by a comma and space, with no comma, space or newline at the end.
void display(const double array[], int arraySize);

const int ARR_CAP = 100;

int main(int argc, char *argv[]) {

// verify file name provided on command line

// open file and verify it opened

// Declare an array of doubles of size ARR_CAP.

  
// Fill the array with up to ARR_CAP doubles from the file entered at the command line.

  
// Call the mean function passing it this array and output the
// value returned.
  
// Ask the user for the index (0 to size - 1) of the value they want to remove.

  
// Call the display function to output the array.

// Call the remove function to remove the value at the index
// provided by the user.
  
  
// Call the display function again to output the array
// with the value removed.

// Call the mean function again to get the new mean

   return 0;
}

Answer 1

#include<iostream>
#include<fstream>
using namespace std;
double mean(const double array[], int arraySize);
void remove(double array[], int &arraySize, int index);
void display(const double array[], int arraySize);
const int ARR_CAP = 100;

int main(int argc, char *argv[])
{
   ifstream infile; //declare file object
   int i,index,size;
   double mn;
   if(argc!=2) //check the validity of command
   {
      cout<<endl<<"Invalid file name or command.";
      exit(0);
       }
       //open the file specified in command line
       infile.open(argv[1]);
       //check for opened or not
       if(!infile)
       {
          cout<<endl<<"Unable to open the file";
          exit(0);
       }
       //declare an array of double with size ARR_CAP
double arr[ARR_CAP];
//loop to read ARR_CAP numbers from file
       for(i=0;i<ARR_CAP;i++)
       infile>>arr[i]; //store the numbers into the array
       //assign the value of ARR_CAP into size, because ARR_CAP is a constant value
       //so after remove function it can not be reduced so we will use size.
   size=ARR_CAP;     
   cout<<endl<<"Mean of array elements are : "<<mean(arr,size)<<endl;
//loop to validate the index. It will accept the values between 0 and ARR_CAP-1(INCLUSIVE)
   do
   {
   cout<<endl<<"Enter the index to delete the element";
   cin>>index;  
   }while(index<0 || index>=size);
   cout<<endl<<"ARRAY ELEMENTS BEFORE REMOVAL:\n";
   display(arr,size); //call to display function
   //call to remove function
   remove(arr,size,index);
   cout<<endl<<"ARRAY ELEMENTS AFTER REMOVAL:\n";
   //call to display function
       display(arr,size);
       //call to mean()
       cout<<endl<<"Mean of array elements are : "<<mean(arr,size)<<endl;
}
//method to remove the array element from the index provided
void remove(double array[], int &arraySize, int index)
{
   int i;
   //loop to shift the numbers upward fromthe index
   for(i=index;i<arraySize;i++)
   {
       array[i]=array[i+1]; //shift the numbers upward
   }
   arraySize=arraySize-1;//update the size of array
}
//method to compute the mean of the array elements
double mean(const double array[], int arraySize)
{
    int i;
    double sum=0; //declare sum and initialize it to 0
    for(i=0;i<arraySize;i++)
    {
       sum=sum+array[i]; //find the sum of all numbers
   }
   return sum/arraySize; //return the mean
}
//method to display the numbers
void display(const double array[], int arraySize)
{
    int i;
    for(i=0;i<arraySize;i++)
    {
        if(i%15==0) //condition is uded just for print the numbers in formatted manner
        cout<<endl;
        if(i!=arraySize-1)
        cout<<array[i]<<", ";//printh the array elements by using comma and space
        else
           cout<<array[i];//print the las element
   }
}

OUTPUT

PROVIDE THE FILE NAME IN PARAMETER WHICH RESIDES IN EXECUTE MENU