Java棧模擬遞歸之斐波那契數列

public class Solution {
    public static int Fibonacci(int num){
        if (num <  2){
            return num;
        }
        return Fibonacci(num - 1) + Fibonacci(num - 2);
    }

    public static int FibonacciStack(int num){
        Stack<Integer> stack = new Stack<Integer>();
        stack.push(num);
        int res = 0;
        while (!stack.empty()){
            int data =  stack.pop();
            if (data < 2){
                res = res + data;
            }else{
                stack.push(data - 1);
                stack.push(data - 2);
            }
        }
        return res;
    }



    public static void main(String[] args){
        System.out.println(FibonacciStack(15));
        System.out.println(Fibonacci(15));
    }
}