Question

STL vector C++

	/* ---- OUTPUT ---- Enter test scores (-1 to quit) Enter a score:  77 Enter a score:  83 Enter a score:  99 Enter a score:  67 Enter a score:  88 Enter a score:  -1 The average score is 82.8.

Write a program in C++ that prompts the user to

  Enter test scores (-1 to quit)

   (see output)

The program calculates and displays

  the average of the test scores.

• Use a vector to hold the values
  • double data type
• Pass the vector to a function named:  getScores
  • Use this function to get the scores.
  • The user can enter as many scores, and then press -1 to stop.
• Then pass the vector to a function named:  calcAvg
  • In this function, add up all values in the vector, then

  calculate and return the average to main()

• Finally, call a function named:  displayAvg
  • Display the average of the test scores.

Answer 1

#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

vector<double> a;
void getScores();
float calcAvg(vector<double> &a);
void displayAvg();

int main()
{

getScores();
displayAvg();
return(0);

}

void getScores()
{
   double mark,d;
   cout<<"\nEnter a score(-1 to quit):";
   cin>>mark;
   while(mark!=-1)
   {
       a.push_back(mark);
       cout<<"\nEnter a score(-1 to quit):";
       cin>>mark;
   }
}
float calcAvg(vector<double> &a){
   float sum;   
   for(int i=0; i<a.size();i++)
   {
       sum += a[i];
   }
   float avg = sum/a.size();
   return avg;
}
void displayAvg()
{
   cout << "The Average Score is "<<calcAvg(a);
}