#include<stdio.h>

#include <time.h>

    

int Fibo(int n)  

{  

if(n<=2)  

 

 

return 1;

else

 return Fibo(n-1)+Fibo(n-2);   

}  

int main()  

{   clock_t start, finish;

    double  duration;

 

 

    int n;  

printf("请输入下标:");

    scanf("%d",&n);  

start = clock();

 

 

    printf("%d\n",Fibo(n));  

finish = clock();

duration = (double)(finish - start) / CLOCKS_PER_SEC;

    printf("用时: %f seconds\n", duration);

    return 0;  

}