XMU 1615 刘备闯三国之三顾茅庐（三） 【欧拉函数+快速幂+欧拉定理】

 1 /****************************************************
 2      
 3     Author : Coolxxx
 4     Copyright 2017 by Coolxxx. All rights reserved.
 5     BLOG : http://blog.csdn.net/u010568270
 6      
 7 ****************************************************/
 8 #include<bits/stdc++.h>
 9 #pragma comment(linker,"/STACK:1024000000,1024000000")
10 #define abs(a) ((a)>0?(a):(-(a)))
11 #define lowbit(a) (a&(-a))
12 #define sqr(a) ((a)*(a))
13 #define mem(a,b) memset(a,b,sizeof(a))
14 const double EPS=1e-8;
15 const int J=10;
16 const int MOD=100000007;
17 const int MAX=0x7f7f7f7f;
18 const double PI=3.14159265358979323;
19 const int N=1004;
20 const int M=1004;
21 using namespace std;
22 typedef long long LL;
23 double anss;
24 LL aans;
25 int cas,cass;
26 LL n,m,lll,ans;
27 LL euler(LL x)
28 {
29     LL res=x;
30     int i;
31     for(i=2;1LL*i*i<=x;i++)
32     {
33         if(x%i==0)
34         {
35             res=res/i*(i-1);
36             while(x%i==0)x/=i;
37         }
38     }
39     if(x>1)res=res/x*(x-1);
40     return res;
41 }
42 LL mi(LL x,LL y,LL mod)
43 {
44     LL s=1;
45     while(y)
46     {
47         if(y&1)s=(s*x)%mod;
48         y/=2;
49         x=(x*x)%mod;
50     }
51     return s;
52 }
53 LL cal(LL a,LL c)
54 {
55     LL e=euler(c);
56     if(a==3 && e>9)return 9%c;
57     if(a==2 && e>2)return 2%c;
58     if(a==1)return 1;
59     if(c==1)return 0;
60     LL b=cal(a-1,e);
61     return (1LL*mi(a,b,c)*mi(a,e,c))%c;
62 }
63 int main()
64 {
65     #ifndef ONLINE_JUDGE
66     freopen("1.txt","r",stdin);
67 //  freopen("2.txt","w",stdout);
68     #endif
69     int i,j,k;
70     int x,y,z;
71 //  for(scanf("%d",&cass);cass;cass--)
72 //  for(scanf("%d",&cas),cass=1;cass<=cas;cass++)
73 //  while(~scanf("%s",s))
74     while(~scanf("%lld",&n))
75     {
76         scanf("%lld",&m);
77         printf("%lld\n",cal(n,m));
78     }
79     return 0;
80 }
81 /*
82 //
83  
84 //
85 */