习题4-11 兔子繁衍问题

 1 #include<stdio.h>
 2 int rabbit(int month);
 3 
 4 int main()
 5 {
 6     int n;
 7     scanf_s("%d", &n);
 8     int month=0;
 9     
10     while (rabbit(month)<n)
11     {
12         month++;
13     }
14     
15     printf("%d\n", month);
16 
17     return 0;
18 }
19 int rabbit(int month)
20 {
21     int a, b, c, i;
22     a = b = 1;
23     if (month == 0)
24     {
25         return 0;
26     }
27     else
28     {
29         if (month == 1 || month == 2)
30         {
31             return 1;
32         }
33         else
34         {
35             for (i = 3; i <= month; i++)
36             {
37                 c = a;
38                 a = b;
39                 b = a + c;
40             }
41             return b;
42         }
43     }
44 }