#include <stdio.h>
//递归
int Fibonacci(int n)
{
    switch(n)
    {
    case 0:
        return 0;
    case 1:
        return 1;
    default:
        return Fibonacci(n - 1) + Fibonacci(n - 2);
    }
}

//非递归
int nonrecursionFibonacci(int n)
{
    int a = 0, b = 1;
    int i;
    switch(n)
    {
    case 0:
        return 0;
    case 1:
        return 1;
    default:
        {
            for (i = 0; i < n - 1; i++)
            {
                int c = a + b;
                a = b;
                b = c;
            }
            return b;
        }
    }
}

int main()
{
    int f = Fibonacci(4);
    int ff = nonrecursionFibonacci(4);
    printf("%d,%d",f,ff);
    return 0;
}