10^9 above prime number determination, Miller_rabin algorithm

#include <iostream> #include <cstdio> #include <ctime> #include <string.h> #include < Stdlib.h> #define LL Long longusing namespace Std;const int s=20;//random algorithm judgment number, S larger, the smaller the probability of error will ans;//given a number, judging whether it is a prime (commonly used long    Long large number) ll Mult_mod (ll a,ll b,ll MoD)//(A*B)%c a,b,c<2^63{a%=mod;    B%=mod;    LL ans=0;            while (b) {if (b&1) {ans=ans+a;        if (ans>=mod) Ans=ans-mod;        } a=a<<1;        if (a>=mod) A=a-mod;    b=b>>1; } return ans;    ll Pow_mod (ll a,ll b,ll MoD)//a^b%mod{LL Ans=1;    A=a%mod;        while (b) {if (b&1) {ans=mult_mod (ans,a,mod);        } a=mult_mod (A,a,mod);    b=b>>1; } return ans; Based on A, n-1=x*2^t a^ (n-1) =1 (mod n) verifies that n is composite//must be composite return true, not necessarily return Falsebool check (ll a,ll n,ll X,ll t) {ll ret=pow_mod    (A,x,n);    LL Last=ret;        for (int i=1;i<=t;i++) {ret=mult_mod (ret,ret,n); if (Ret==1 &&    Last!=1 && last!=n-1) return true;//composite Last=ret;    } if (ret!=1) return true; else return false;} Miller_rabin () algorithm prime number determination//is a prime number to return true.    (may be a pseudo prime, but the probability is very small)//Composite Returns False;bool Miller_rabin (Long long N) {if (n<2) return false;    if (n==2) return true;    if ((n&1) ==0) return false;//even LL x=n-1;    LL t=0;    while ((x&1) ==0) {x>>=1;t++;} for (int i=0;i<s;i++) {LL a=rand ()% (n-1) +1;//rand () requires Stdlib.h header file if (check (a,n,x,t)) return Fals e;//Composite} return true;    void find (Long long n,int c) {if (n==1) return;        if (Miller_rabin (n)) {//m[n]++;        Ans=min (Ans,n);    return;    } Long long p=n;    while (p>=n) P=pollard_rho (p,c--);    Find (P,C); Find (n/p,c);}   int main () {int A;   scanf ("%d", &a);       while (a--) {long long x;       scanf ("%lld", &x);       if (Miller_rabin (x)) cout<< "Prime" <<endl;        else{find (x,12312); Cout<<ans<<endL }   }}

　　

10^9 above prime number determination, Miller_rabin algorithm