详见PoPoQQQ的博客..
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1 2 #include <iostream> 3 #include <cstring> 4 #include <cstdio> 5 #include <algorithm> 6 #define LL long long 7 using namespace std; 8 LL KASE,p; 9 inline LL Get_Phi(LL x) 10 { 11 LL Ret=x; 12 for (LL i=2;i*i<=x;i++) 13 if (x%i==0) 14 { 15 Ret/=i;Ret*=(i-1); 16 while (x%i==0) x/=i; 17 } 18 if (x>1) Ret/=x,Ret*=(x-1); 19 return Ret; 20 } 21 inline LL Pow(LL Base,LL Exp,LL Mod) 22 { 23 LL Ret=1; 24 while (Exp) 25 { 26 if (Exp&1) Ret=(Ret*Base)%Mod; 27 Exp>>=1; Base=(Base*Base)%Mod; 28 } 29 return Ret; 30 } 31 LL Solve(LL p) 32 { 33 if (p==1) return 0; 34 LL Exp=0; 35 while (!(p&1)) p>>=1,Exp++; 36 LL Phi=Get_Phi(p); 37 LL Tmp=Solve(Phi); 38 (Tmp+=Phi-Exp%Phi)%=Phi; 39 Tmp=Pow(2,Tmp,p)%p; 40 return Tmp<<Exp; 41 42 } 43 int main() 44 { 45 scanf("%lld",&KASE); 46 for (LL Kase=1;Kase<=KASE;Kase++) 47 { 48 scanf("%lld",&p); 49 printf("%lld\n",Solve(p)); 50 } 51 return 0; 52 }