Quadratic primes

프로젝트 오 일 러 의 27 번 문제 입 니 다. 문 제 는 해석 하기 가 좀 길 어 요. 링크 를 넣 어 주세요.https://projecteuler.net/problem=27

#include
#include

using namespace std;

const int S = 8;

long long mult_mod(long long a, long long b, long long c){
     
    a%= c;
    b%= c;
    long long ret = 0;
    long long tmp = a;
    while (b)
    {
     
        if(b&1){
     
            ret += tmp;
            if(ret>c) ret-=c;
        }
        tmp <<=1;
        if(tmp>c) tmp -=c;
        b >>=1;
    }
    return ret;
}

long long pow_mod(long long a, long long n, long long mod){
     
    long long ret = 1;
    long long temp = a%mod;
    while (n)
    {
     
        if(n&1) ret = mult_mod(ret, temp, mod);
        temp = mult_mod(temp, temp, mod);
        n >>=1;
    }
    return ret;
}

bool check(long long a,long long n, long long x, long long t){
     
    long long ret = pow_mod(a,x,n);
    long long 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;
        last = ret;
    }
    if(ret !=1) return true;
    return false; 
}

bool Miller_Rabin(long long n){
     
    if(n<2) return false;
    if(n==2) return true;
    if((n&1)==0) return false;
    long long x = n-1;
    long long t=0;
    while ((x&1)==0){
     x>>=1;t++;};
    srand(time(NULL));
    for(int i=0;i<S;i++){
     
        long long a = rand()%(n-1) +1;
        if(check(a,n,x,t)) return false;
    }
    return true; 
}


int main(){
     
    int res = 0;
    int ans = 0;
    vector<int> bv = {
     2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,\
    151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,\
    353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,\
    557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,\
    751,757,761,769,773,787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,971,977,983,991,997};
    for(int i=-999;i<1000;i++){
     
        for(auto j:bv){
     
            int n=1;
            while(Miller_Rabin(n*n+i*n+j))
            {
     
                n++;
            }
            if(n>res) ans = i*j;
            res = max(res,n);
        }
    }
    cout<< res<<" "<<ans<<endl;
    return 0;
}