Answer:
The program in C++ is as follows:
#include <iostream>
using namespace std;
double *sum_n_avg(double n1, double n2, double n3);
int main () {
double n1, n2, n3;
cout<<"Enter 3 inputs: ";
cin>>n1>>n2>>n3;
double *p;
p = sum_n_avg(n1,n2,n3);
cout<<"Sum: "<<*(p + 0) << endl;
cout<<"Average: "<<*(p + 1) << endl;
return 0;
}
double *sum_n_avg(double n1, double n2, double n3) {
static double arr[2];
arr[0] = n1 + n2 + n3;
arr[1] = arr[0]/3;
return arr;
}
Step-by-step explanation:
This defines the function prototype
double *sum_n_avg(double n1, double n2, double n3);
The main begins here
int main () {
This declares variables for input
double n1, n2, n3;
This prompts the user for 3 inputs
cout<<"Enter 3 inputs: ";
This gets user inputs
cin>>n1>>n2>>n3;
This declares a pointer to get the returned values from the function
double *p;
This passes n1, n2 and n3 to the function and gets the sum and average, in return.
p = sum_n_avg(n1,n2,n3);
Print sum and average
cout<<"Sum: "<<*(p + 0) << endl;
cout<<"Average: "<<*(p + 1) << endl;
return 0;
}
The function begins here
double *sum_n_avg(double n1, double n2, double n3) {
Declare a static array
static double arr[2];
Calculate sum
arr[0] = n1 + n2 + n3;
Calculate average
arr[1] = arr[0]/3;
Return the array to main
return arr;
}