Guess the output of this recursion problem.

#include"iostream"

using namespace std;

void func(int bool)

{

if(!bool)

return 0;

cout<<bool;

func(!bool);

cout<<bool;

}

int main()

{

func(123);

}

What is the output?

1. 123123

2, 123

3. Stack Overflow

4. 0

#cprogramming #cpluplus #cprogramming #recursion