c++ biginteger example

Example 1: bigint c++

//Bigint.hpp class
#ifndef BIGINT_HPP
#define BIGINT_HPP

#define BASE 10

#include <iostream>
#include <list>
#include"Command.hpp"
class Bigint {
public:
  Bigint() = default;  // Construct expect no arg 
  Bigint(const Bigint&) = default; // Copy constructor 
  Bigint(Bigint&&) = default; // Move constructor
  Bigint& operator=(const Bigint&) = default; // Copy assignment 
  Bigint& operator=(Bigint&&) = default; // Move assignment 
  ~Bigint(); // Destructort 
  Bigint(std::list<unsigned char>B);
  // Accessors methods ########################################################################
  bool is_zero()const;

  bool is_negative() const;

  // Friends ####################################################################################
  friend Bigint operator+(const Bigint& a, const Bigint& b);
  friend Bigint operator-(const Bigint& a, const Bigint& b);
  friend Bigint operator*(const Bigint& a, const Bigint& b);

  friend std::ostream& operator<<(std::ostream& out, const Bigint& i);
  friend std::istream& operator>>(std::istream& in, Bigint& i);
  friend Bigint minus_operator_cases(const Bigint& a, const Bigint& b);
private:
  //! Determine whether the integer is negative.
  bool m_is_negative = false;

  //! A linked list of digits.
  std::list<unsigned char> m_digits;
};

Bigint operator+(const Bigint& a, const Bigint& b);
Bigint operator-(const Bigint& a, const Bigint& b);
Bigint operator*(const Bigint& a, const Bigint& b);
std::ostream& operator<<(std::ostream& out, const Bigint& i);
std::istream& operator>>(std::istream& in, Bigint& i);
#endif

Example 2: bigint c++

// bigint methods implementation
#include <stdexcept>
#include"Bigint.hpp"
#include<algorithm>
//+++++++++++++++++++++++++++    overloaded pluse operator    ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// ++++++++++++++++++++++++++++        Amir Ammar             +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bigint operator+(const Bigint& a, const Bigint& b){
  Bigint temp1 = a;
  Bigint temp2 = b;
  Bigint temp3;
  if(temp1.is_zero()&&temp2.is_zero()){temp3.m_digits={'0'};return temp3;}
  if(!temp1.is_negative() &&temp2.is_negative()){  // if  (+temp1) (+) (-temp2)  done 
    temp2.m_is_negative = false;
    temp3 = temp1-temp2;
    return temp3;
  }
  if(temp1.is_negative()&&!temp2.is_negative()){ // if  (-temp1) (+)  (+temp2)   done 
    temp1.m_is_negative = false;
    temp3 = temp2-temp1;
    return temp3;
  }
  int carry {0}; int sum{0};auto it1 = temp1.m_digits.rbegin(); auto it2 = temp2.m_digits.rbegin();
  while(it1 != temp1.m_digits.rend() && it2 != temp2.m_digits.rend() ){
    ((a.m_digits.size()>b.m_digits.size()))?temp2.m_digits.push_front('0'):temp1.m_digits.push_front('0');
    sum=((*it1-'0')+(*it2-'0')+carry);
    temp3.m_digits.emplace_front(sum%10+'0');
    carry=sum/10;
    ++it1; ++it2;
  }
  if(carry != 0)temp3.m_digits.emplace_front(carry+'0');
  if(temp1.is_negative()&&temp2.is_negative()) // if (-temp1) + (-temp2) done
  { 
    temp3.m_digits.emplace_front('-'); // we push eventually (-)
  }
  return temp3;
}
//-------------------------------- overloaded  minus operator ---------------------------------------- 
//--------------------------------------   Amir Ammar   ----------------------------------------
Bigint operator-(const Bigint& a,const Bigint& b)
{ 
  Bigint temp1(a);
  Bigint temp2(b);
  Bigint sub;
  if(temp1.is_zero()&&temp2.is_zero()){sub.m_digits={'0'};return sub;}
  if(!temp1.is_negative()&& temp2.is_negative()){  // (+temp1) - (-temp2) 
     temp2.m_is_negative = false;
     return temp1+temp2;    
  }
  if(temp1.is_negative() && !temp2.is_negative()){  // (-temp1) - (+temp2) 
     temp2.m_is_negative = true;
     return temp1+temp2;    
  }
  if(temp1.is_negative()&&temp2.is_negative()){
    temp1.m_is_negative = false;
    temp2.m_is_negative = false;
    return temp2 - temp1 ;
  }
  auto it_1 = temp1.m_digits.end(); 
  auto it_2 = temp2.m_digits.end(); 
  int one_less{0};
  int length = temp1.m_digits.size()-temp2.m_digits.size();
  if(length <0){
    for(int i = length ; i<0; ++i) // 
    ((temp1.m_digits.size()>temp2.m_digits.size())?temp2.m_digits.emplace_front('0'):temp1.m_digits.emplace_front('0'));
  }else
  {
    for(int i = length; i>0; --i)
      ((temp1.m_digits.size()>temp2.m_digits.size())?temp2.m_digits.emplace_front('0'):temp1.m_digits.emplace_front('0'));
  }
  auto it1 = temp1.m_digits.end(); auto it2 = temp2.m_digits.end();
  while(it1 != temp1.m_digits.begin() && it2 != temp2.m_digits.begin()){
      --it1; --it2; 
      int it1_int = *it1%48;
      int it2_int = *it2%48;
    if(it1_int-it2_int-one_less<0){
      it1_int+= 10;
      sub.m_digits.emplace_front(it1_int-it2_int-one_less+'0');
      one_less = 1;
    }else{
      sub.m_digits.emplace_front(it1_int-it2_int-one_less+'0');
      one_less = 0;
    }
  }
  if(one_less==1){
    sub=temp2-temp1 ;
    sub.m_digits.emplace_front('-');
  }
  while(sub.m_digits.front()=='0'&&sub.m_digits.size()!= 1){
    sub.m_digits.pop_front();
    if(sub.m_digits.size()== 1)
      break;
  }
  return sub.m_digits;
}