poj1284 Primitive Roots

Consider the two number a < N of Coprime, A is the root of n when and only if P <φ (n) has AP mod n≠1 (φ (n) is the Euler function of N).

Also equivalent to the set AP (P <φ (n)) is equal to the simplified remainder of N.

Determines whether a (< N) is the original followed method of N:

Calculate φ (n) of the mass factor set {P1, p2, ..., PK), if Aφ (n)/pi mod n≠1, then A is the original root of N.

Such a is a total of φ (φ (n)).

http://poj.org/problem?id=1284

1#include <cstdio>2#include <cmath>3 using namespacestd;4 intN;5 intprime[ -], K;6 7 voidsolve () {8     intm = n-1;9K =0;Ten     if(M%2==0){ Oneprime[k++] =2; A          while(M%2==0) m/=2; -     } -     intMID = (int) sqrt (m); the      for(inti =3; I <= mid; i + =2){ -         if(m% i = =0){ -prime[k++] =i; -              while(m% i = =0) m/=i; +MID = (int) sqrt (m); -         } +     } A     if(M! =1) prime[k++] =m; at     intAns = n-1; -      for(inti =0; I < K; i++) ans/=Prime[i]; -      for(inti =0; I < K; i++) ans *= prime[i]-1; -printf"%d\n", ans); - } -  in intMain () { -      while(~SCANF ("%d", &N)) solve (); to     return 0; +}

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poj1284 Primitive Roots