Thread: How to stop user from entering same number twice?

i need to create a program that will accept 5 numerical inputs and determine the highest, and i also need to stop user from using the same number twice and do not count it from the 5 numerical inputs. kindly help me, here is my code

Code:

int number,x,j=5;
int max=0;
int main(){
    do{
    for(int i=0; i<j; i++)
    {
    cout<<"\nInput number :";
    cin>>number;
    if(number>max)
    {
    max = number;
    x=0;
    }

    else if (number == max)
    {
    cout<<"\nDo not use the same number twice! Please Try again!";
    i--;
    x=1;
    }
    }

    }while(x==1);

    cout<<"The highest number is: "<<max;

    getch();
    clrscr();
    return 0;
}

You can use set<int> and check the std::set's insert signature if insertion was successful or not

Code:

#include <iostream>
#include <set>


using namespace std;
const int SIZE = 5;


int main()
{
    set<int> numbers;
    int counter{};
    do
    {
        cout << "Enter number: \n";
        int num;
        cin >> num;//recommned some input validation as well;
        if(numbers.insert(num).second)
        {
            counter++;
        }
        else
        {
            cout << "Duplicate number, try again \n";
        }
    } while (counter < SIZE);
}

oops Sean

Code:

int counter{};

value initialization - cppreference.com
Though to be consistent I should probably have also used

Code:

constexpr auto SIZE = 5;

I knew that was added for class types in C++ 11 but I've never seen initialisation list used to initialise a single primitive type like that. Learn something new every day. I don't really like it personally as I prefer my code to read like English. I would have used the good old fashioned = 0 notation myself.

It's not an initialization list. It's a new constructor syntax. And it does lead to some nasty unexpected consequences with regards to std::vector but that's about it.

You can now just type:

Code:

int x{1337};
// vs
int y(1337);

Now the difference pops a lot more.

Hey guys, I forgot to tell you that I am obliged to use Turbo C Compiler.

Whoever is mandating that you to use Turbo C is doing you an extreme disservice. That compiler has been obsolete for decades.

Do yourself a favor - get a modern book, get a compiler/IDE from this millennium, and continue the learning process on your own. You can still "fake it" in class if you need to make grades.