欧拉降幂 （a^t)%c 模板

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 ll a,c,p,mod;
 5 char t[1001];
 6 ll phi(ll n)
 7 {
 8     ll res=n;
 9     for(int i=2;i*i<=n;i++){
10         if(n%i==0){
11             res=res/i*(i-1);
12             while(n%i==0)
13                 n/=i;
14         }
15     }
16     if(n>1)
17         res=res/n*(n-1);
18     return res;
19 }
20 ll quickpower(ll a,ll b,ll c)
21 {
22     ll ans=1;
23     while(b)
24     {
25         if(b&1)
26             ans=(ans*a)%c;
27         a=(a*a)%c;
28         b>>=1;
29     }
30     return ans;
31 }
32 int main()
33 {
34     while(~scanf("%lld%s%lld",&a,t,&c)){
35         int len=strlen(t);
36         ll p=phi(c);
37         ll ans=0;
38         for(ll i=0;i<len;i++)
39             ans=(ans*10+t[i]-'0')%p;
40         ans+=p;
41         printf("%lld\n",quickpower(a,ans,c));
42     }
43 }