Question

WRITE A COMPLETE PROGRAM IN C++

A. Ask users to input two positive integers a and b (a < b). You need to do error checking in this stage to make sure the input is correct. For example, a = 1, b = 50.

B. Write a separate function, isEven() to list all even within [a, b] inclusive.

C. n the main function, print a, b and the list of even numbers.

Answer 1

//HERE IS YOUR CODE

#include <iostream>

#include <vector>

using namespace std;

int a, b;

vector <int> isEven()//this function will return the list of even numbers between a and b

{

vector <int> evens;

for(int i=a;i<=b;i++)//interating from a to b

{

if(i%2==0)evens.push_back(i);//if i is divisible by 2 then it is even, and it is pushed to the list

}

return evens;//returning the list of the even numbers

}

int main()

{

cout<<"Enter the values of a and b respectively: "<<endl;

cin>>a>>b;//taking input of a and b

while(a>=b)//if input is not proper (i.e. a>=b)

{

cout<<"Invalid entry, value of a must be strictly lesser than b."<<endl;

cout<<"Enter the values of a and b respectively: "<<endl;

cin>>a>>b;//taking the input again

}

vector <int> ans=isEven();//ans will contain the list of all the even numbers between a and b

//printing the results

cout<<"a= "<<a<<endl;

cout<<"b= "<<b<<endl;

cout<<"Even numbers between a and b are:"<<endl;

for(auto it: ans)//printing the even numbers

{

cout<<it<<endl;

}

return 0;

}