BigPrimeField.hpp

#ifndef _BIG_PRIME_FIELD_H_
#define _BIG_PRIME_FIELD_H_

#include "BPASFiniteField.hpp"
#include <iostream>
#include <string>

using std::endl;
using std::cout;

//forward declarations
class Integer;
class RationalNumber;
class ComplexRationalNumber;
class SmallPrimeField;
class GeneralizedFermatPrimeField;
class DenseUnivariateIntegerPolynomial;
class DenseUnivariateRationalPolynomial;
template <class Ring>
class SparseUnivariatePolynomial;

// prime field with big number, using GMP functions
/**
 * A prime field whose prime can be arbitrarily large.
 */
class BigPrimeField : public BPASFiniteField<BigPrimeField> {

private:

    static mpz_class prime;
    mpz_class a;

public:

    static mpz_class characteristic;
    // static bool isPrimeField;
    // static bool isSmallPrimeField;
    // static bool isComplexField;

    BigPrimeField ();

    BigPrimeField (mpz_class _a);

    BigPrimeField (long int _a);

    BigPrimeField (const BigPrimeField& c);

    explicit BigPrimeField (const Integer& c);

    explicit BigPrimeField (const RationalNumber& c);

    explicit BigPrimeField (const ComplexRationalNumber& c);

    explicit BigPrimeField (const SmallPrimeField& c); //? NOT SURE

    explicit BigPrimeField (const GeneralizedFermatPrimeField& c);

    explicit BigPrimeField (const DenseUnivariateIntegerPolynomial& c);

    explicit BigPrimeField (const DenseUnivariateRationalPolynomial& c);

    explicit BigPrimeField (const SparseUnivariatePolynomial<Integer>& c);

    explicit BigPrimeField (const SparseUnivariatePolynomial<RationalNumber>& c);

    explicit BigPrimeField (const SparseUnivariatePolynomial<ComplexRationalNumber>& c);

    template <class Ring>
    explicit BigPrimeField (const SparseUnivariatePolynomial<Ring>& c);

    BigPrimeField* BPFpointer(BigPrimeField* b);

    BigPrimeField* BPFpointer(RationalNumber* a);

    BigPrimeField* BPFpointer(SmallPrimeField* a);

    BigPrimeField* BPFpointer(GeneralizedFermatPrimeField* a);

    static void setPrime(mpz_class p){
        prime = p;
        characteristic = p;
    }

    mpz_class getCharacteristic() const override {
        return characteristic;
    }


    mpz_class Prime() const;

    mpz_class number() const;

    void whichprimefield();

    BigPrimeField findPrimitiveRootOfUnity(long int n) const {
        return BigPrimeField::findPrimitiveRootofUnity(mpz_class(n));
    }


    static BigPrimeField findPrimitiveRootofUnity(mpz_class n){
        if ( ((prime - 1) % n != 0)){
            cout << "ERROR: n does not divide prime - 1." << endl;
            return -1;
        }
        bool flag = false;
        mpz_class  q = (prime - 1) / n;
        BigPrimeField p1 (prime - 1);
        BigPrimeField c;
        int i = 0;
        mpz_class test = q * n / 2;
        srand (time(NULL));
        while(i < 20){
            c =  rand();
            if ((c^test) == p1) {
                flag = true;
                return (c^q);
            }
            i++;
        }
        if (!flag ){
            cout << "No primitive root found!"<< endl;
            return 0;
        }
    // If no primitive root found
        return 0;
    }

    BigPrimeField unitCanonical(BigPrimeField* u = NULL, BigPrimeField* v = NULL) const;

    BigPrimeField& operator= (const BigPrimeField& c);

    BigPrimeField& operator= (long int k);

    BigPrimeField& operator= (const mpz_class& k);

    inline bool isZero() const {
        return (a == 0);
    }

    inline void zero() {
        a = 0;
    }

    inline bool isOne() const {
        return (a == 1);
    }

    inline void one() {
        a = 1;
    }

    inline bool isNegativeOne() const {
        return (a == (prime - 1));
    }

    inline void negativeOne() {
        a = prime - 1;
    }

    inline int isConstant() const {
        if (a >= 0)
            return 1;
        else { return -1; }
    }

    inline bool operator== (const BigPrimeField& c) const {
        if (a == c.a)
            return 1;
        else { return 0; }
    }

    inline bool operator== (const mpz_class& k) const {
        BigPrimeField r (*this);
        BigPrimeField b (k);
        if (b == r){
            return 1;
        }
        else {
            return 0;
        }
    }

    inline bool operator== (long int k) const {
        BigPrimeField r (*this);
        BigPrimeField b (k);
        if (b == r){
            return 1;
        }
        else {
            return 0;
        }
    }

    inline bool operator!= (const BigPrimeField& c) const {
        if (a == c.a)
            return 0;
        else { return 1; }
    }

    inline bool operator!= (const mpz_class& k) const {
        BigPrimeField r (*this);
        BigPrimeField b (k);
        if (b == r){
            return 0;
        }
        else {
            return 1;
        }
    }

    inline bool operator!= (long int k) const {
        BigPrimeField r (*this);
        BigPrimeField b (k);
        if (b == r){
            return 0;
        }
        else {
            return 1;
        }
    }

    inline BigPrimeField operator+ (const BigPrimeField& c) const {
        BigPrimeField r (*this);
        return (r += c);
    }

    inline BigPrimeField operator+ (long int c) const {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return (r += b);
    }

    inline BigPrimeField operator+ (const mpz_class& c) const {
        BigPrimeField r (*this);
        BigPrimeField b(c);
        return (r += b);
    }

    inline BigPrimeField& operator+= (const BigPrimeField& c) {
        a = (a + c.a);
        if(a>prime)
            a -= prime;
        return *this;
    }

    inline BigPrimeField operator+= (long int c) {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return (r += b);
    }

    inline BigPrimeField operator+= (const mpz_class& c) {
        BigPrimeField r (*this);
        BigPrimeField b(c);
        return (r += b);
    }

    inline BigPrimeField operator- (const BigPrimeField& c) const {
        BigPrimeField r (*this);
        return (r -= c);
    }

    inline BigPrimeField operator- (long int c) const {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return (r += b);
    }

    inline BigPrimeField operator- (const mpz_class& c) const {
        BigPrimeField r (*this);
        BigPrimeField b(c);
        return (r += b);
    }

    inline BigPrimeField& operator-= (const BigPrimeField& c) {
        if ((a - c.a)<0){
            a = prime+(a - c.a);
        }
        else{
            a = a - c.a;
        }
        return *this;
    }

    inline BigPrimeField operator-= (long int c) {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return (r += b);
    }

    inline BigPrimeField operator-= (const mpz_class& c) {
        BigPrimeField r (*this);
        BigPrimeField b(c);
        return (r += b);
    }

    inline BigPrimeField operator- () const {
        BigPrimeField ret = *this;
        ret.a = prime - a;
        return ret;
    }

    inline BigPrimeField operator* (const BigPrimeField& c) const {
        BigPrimeField r (*this);
        return (r *= c);
    }

    inline BigPrimeField operator* (const mpz_class& c) const {
        BigPrimeField r (*this);
        return (r *= c);
    }

    inline BigPrimeField operator* (long int c) const {
        BigPrimeField r (*this);
        return (r *= c);
    }

    inline BigPrimeField& operator*= (const BigPrimeField& c) {
        a = (a * c.a)%prime;
        return *this;
    }

    inline BigPrimeField& operator*= (const mpz_class& m) {
        mpz_class c(m);
        while(c<0){
            c=c+prime;
        }
        a = (a * c)%prime;
        return *this;
    }

    inline BigPrimeField& operator*= (long int c) {
        mpz_class b = c;
        while(b<0){
            b=b+prime;
        }
        a = (a * b)%prime;
        return *this;
    }

    inline BigPrimeField operator^ (long long int c) const {
        BigPrimeField r (*this);
        mpz_class b(std::to_string(c), 10);
        return (r ^ b);
    }

    inline BigPrimeField operator^ (const mpz_class& exp) const {
        BigPrimeField r;
        mpz_class e = exp;
        if (isZero() || isOne() || e == 1)
            r = *this;
        else if (e == 2) {
            r = *this * *this;
        }
        else if (e > 2) {
            BigPrimeField x (*this);
            r.one();

            while (e != 0) {
                if ((e % 2) == 1)
                    r *= x;
                x = x * x;
                e >>= 1;
            }
        }
        else if (e == 0) {
            r.one();
        }
        else {
            r = *this ^ (-e);
            r=r.inverse();
        }
        return r;
    }

    inline BigPrimeField& operator^= (long long int c) {
        *this = *this ^ c;
        return *this;
    }

    inline BigPrimeField& operator^= (const mpz_class& e) {
        *this = *this ^ e;
        return *this;
    }

    inline ExpressionTree convertToExpressionTree() const {
        return ExpressionTree(new ExprTreeNode(a));
    }

    inline BigPrimeField operator/ (const BigPrimeField& c) const {
        BigPrimeField r (*this);
        return (r /= c);
    }

    inline BigPrimeField operator/ (long int c) const {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return (r /= b);
    }

    inline BigPrimeField operator/ (const mpz_class& c) const {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return (r /= b);
    }

    inline BigPrimeField& operator/= (const BigPrimeField& c) {
        if (c.isZero()) {
            std::cout << "BPAS: error, dividend is zero from SmallPrimeField."<< std::endl;
            exit(1);
        }
        BigPrimeField inv = c.inverse();
        *this *= inv;
        return *this;
    }

    inline BigPrimeField& operator/= (long int c) {
        BigPrimeField b (c);
        return (*this /= b);
    }

    inline BigPrimeField& operator/= (const mpz_class& c) {
        BigPrimeField b (c);
        return (*this /= b);
    }

    inline BigPrimeField operator% (const BigPrimeField& c) const {
        return 0;
    }

    inline BigPrimeField& operator%= (const BigPrimeField& c) {
        *this = 0;
        return *this;
    }

    inline BigPrimeField gcd (const BigPrimeField& other) const {
        BigPrimeField q (0);
        BigPrimeField r (0);
        BigPrimeField c (other);
        BigPrimeField b (*this);
        if(b.a < c.a){
            return c.gcd(b);
        }
        while (c.a > 0) {
            q.a = b.a / c.a;
            r.a = b.a % c.a;
            b = c;
            c = r;
        }
        return b;
    }

    inline BigPrimeField gcd (long int c){
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return r.gcd(b);
    }

    inline BigPrimeField gcd (const mpz_class& c) const {
        BigPrimeField r (*this);
        BigPrimeField b (c);
        return r.gcd(b);
    }

    /**
     * Compute squarefree factorization of *this
     */
    inline Factors<BigPrimeField> squareFree() const {
        std::vector<BigPrimeField> ret;
        ret.push_back(*this);
        return ret;
    }

    /**
     * Get the euclidean size of *this.
     */
    inline Integer euclideanSize() const {
        return Integer(1);
    }

    /**
     * Perform the eucldiean division of *this and b. Returns the
     * remainder. If q is not NULL, then returns the quotient in q.
     */
    BigPrimeField euclideanDivision(const BigPrimeField& b, BigPrimeField* q = NULL) const;

    /**
     * Perform the extended euclidean division on *this and b.
     * Returns the GCD. If s and t are not NULL, returns the bezout coefficients in them.
     */
    BigPrimeField extendedEuclidean(const BigPrimeField& b, BigPrimeField* s = NULL, BigPrimeField* t = NULL) const;

    /**
     * Get the quotient of *this and b.
     */
    BigPrimeField quotient(const BigPrimeField& b) const;

    /**
     * Get the remainder of *this and b.
     */
    BigPrimeField remainder(const BigPrimeField& b) const;

    inline BigPrimeField inverse() const {
        BigPrimeField r(0);
        mpz_t temp;
        mpz_init(temp);
        if (!mpz_invert(temp, a.get_mpz_t(), prime.get_mpz_t()))
            mpz_set_si(temp, 0);
        mpz_class temp_class(temp);
        mpz_clear(temp);
        r = temp_class;
        return r;
    }

};

#endif