"Sword Pointing Offer" Java Implementation - Fibonacci Sequence

Topic description

Everyone knows the Fibonacci sequence, and now you are asked to input an integer n, please output the nth item of the Fibonacci sequence.
n<=39

ideas

Very basic topic, there are two implementation ideas recursive and non-recursive.

code

recursive algorithm

    public class Solution {
        public int Fibonacci(int n) {
            if(n==0)
                return 0;
            else if(n==1)
                return 1;
            else 
                return Fibonacci(n-1)+Fibonacci(n-2);
        }
    }

non-recursive algorithm

    public class Solution {
        public int Fibonacci(int n) {
             int temp = 1;
             int result = 0;
            int temp2 = 1;
            if(n==0)
                    return 0;
            if(n==1||n==2)
                return 1;
            for(int i = 3;i<=n;i++){
                result = temp +temp2;
                temp = temp2;
                temp2 = result;
            }
            return result;
        }
    }