HDOJ 1005 Number Sequence

 1 #include <iostream>
 2 using namespace std;
 3 #define Max 100
 4 int main()
 5 {
 6     unsigned int A,B,n,result,fn[Max]={0};
 7     int i=0;
 8     unsigned int f1,f2;
 9     cin>>A>>B>>n;
10     while(A||B||n)
11     {
12         f1=1;
13         f2=1;
14         fn[0]=(A*f1+B*f2)%7;
15         fn[1]=(A*fn[0]+B*f2)%7;        
16         for(i=2;i<=n;i++)
17         {
18             fn[i]=(A*fn[i-1]+B*fn[i-2])%7;
19             if(fn[i-1]==fn[0]&&fn[i]==fn[1])
20             {
21                 result=fn[(n-3)%(i-1)];//求出周期
22                 break;
23             }
24         }        
25         if(n==1||n==2)
26         {
27             cout<<f1<<endl;
28         }
29         else
30         cout<<fn[(n-3)%(i-1)]<<endl;
31         cin>>A>>B>>n;
32     }
33     return 0;
34 }