Print the number from 1 to entered number and from entered number to 1 using 1 loop,c++

Question

Hello, I am stuck with one problem in c++, I have to enter a number and output needs to be from 1 to entered number and from entered number to 1, but using only one loop. I can't figure it out, what is the catch?

Example:
1
2
3
4
4
3
2
1

Answer 1

Next time please link your attempt first. This will you help:

https://code.sololearn.com/c6GLR0jiwCWk/?ref=app

Answer 2

Yes SIR!, Ty for help.

Answer 3

Maybe this might help

#include <iostream>
using namespace std;

int main() {
int num,key;
cin >> num;

key = num *2 +1;

for (int i=1; i<key; ++i){
if(i <= num){
cout << i << endl;
} else {
cout << key -i << endl;
}
}
return 0;
}