Integer Replacement

integer_replacement.cpp

class Solution {
public:
    int integerReplacement(int n) {
        return helper(n);        
    }
    
private:
    int helper(long n) {
        if (n == 1)
            return 0;
            
        if (n % 2 == 0)
            return 1 + helper(n / 2);
        else
            return 1 + min(helper(n - 1), helper(n + 1));
    }
};