C++ program to implement Collatz Conjecture

In this tutorial, we will be discussing a program to implement Collatz Conjecture.

For this, we will be given with a number n and we have to find out whether it can be converted to 1 using two operations −

• If n is even, n is converted to n/2.

• If n is odd, n is converted to 3*n + 1.

Example

#include<bits/stdc++.h>
using namespace std;
//checking if n reaches to 1 or not
bool check1(int n, unordered_set<int> &s){
   if (n == 1)
      return true;
   if (s.find(n) != s.end())
      return false;
   return (n % 2)? check1(3*n + 1, s) :
      check1(n/2, s);
}
bool if_one(int n){
   unordered_set<int> s;
   return check1(n, s);
}
int main(){
   int n = 234;
   if_one(n) ? cout << "Yes" : cout <<"No";
   return 0;
}

Output

Yes