UVa 11582 (快速幂取模) Colossal Fibonacci Numbers!

 1 #include <cstdio>
 2 #include <iostream>
 3 using namespace std;
 4 
 5 const int maxn = 1000 + 10;
 6 typedef unsigned long long ULL;
 7 int f[maxn][maxn * 6], period[maxn];
 8 
 9 int pow_mod(ULL a, ULL b, int n)
10 {
11     if(b == 0) return 1;
12     int k = pow_mod(a, b/2, n);
13     k = k * k % n;
14     if(b % 2 == 1) k = k * a % n;
15     return k;
16 }
17 
18 int solve(ULL a, ULL b, int n)
19 {
20     if(a == 0 || n == 1) return 0;
21     int p = pow_mod(a % period[n], b, period[n]);
22     return f[n][p];
23 }
24 
25 int main(void)
26 {
27     freopen("11582in.txt", "r", stdin);
28     for(int n = 2; n < maxn; ++n)
29     {
30         f[n][0] = 0, f[n][1] = 1;
31         for(int i = 2; ; ++i)
32         {
33             f[n][i] = (f[n][i-2] + f[n][i-1]) % n;
34             if(f[n][i-1] == 0 && f[n][i] == 1)
35             {
36                 period[n] = i - 1;
37                 break;
38             }
39         }
40     }
41 
42     ULL a, b;
43     int n, T;
44     scanf("%d", &T);
45     while(T--)
46     {
47         cin >> a >> b >> n;
48         printf("%d\n", solve(a, b, n));
49     }
50     
51     return 0;
52 }