斐波那契数列

 1 #include "stdio.h"
 2 #include "math.h"
 3 
 4 
 5 int factorial_tail(int n,int acc1,int acc2)
 6 {
 7     if (n < 2)
 8         return acc1;
 9     else
10         return factorial_tail(n-1,acc2,acc1+acc2);
11 }
12 
13 int factorial_head(int n)
14 {
15     if(n<=2)
16         return 1;
17     else
18         return factorial_head(n-1)+factorial_head(n-2);
19 }
20 
21 int main(void)
22 {
23     int i, n, rs;
24 
25     printf("请输入斐波那契数n：");
26     scanf("%d",&n);
27 
28     rs = factorial_tail(n, 1, 1);
29     //rs=factorial_head(n);
30     printf("%d ", rs);
31 
32     return 0;
33 }