duze_liczby

#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;


// nowy typ danych
// konstruktor, destruktor, operator = + >> <<
// jedna cyfra to co najmniej jeden bajt
// pięć linijek jednej liczby (ok 80 znaków), pięć drugiej, trzecia = 1 + 2, cout trzecia
// http://www.cplusplus.com/forum/beginner/151124/   POMOCNY LINK
class Big_number{
  friend ostream & operator<< (ostream & s1, Big_number & o1);
  friend istream & operator>>(istream & s1, Big_number & o1);
  char* number;
public:

  Big_number(){
    number=NULL;
  }

  ~Big_number(){
    if (number!=""){
      delete [] number;
      number=NULL;
    }
  }

  Big_number(const char* o1){
    for (int i = 0; i < strlen(o1); i++){
    this->number[i] = o1[i];
    }
  }

  Big_number & operator=(const Big_number & o1){
  if (this->number!=NULL){
    delete [] number;
    number = NULL;
  }
  this -> number = new char[strlen(o1.number)];
  for (int i = 0; i< strlen(o1.number); i++){
    this->number[i]=o1.number[i];
  }
  return *this;
  }


  Big_number  operator+(const Big_number &o1){
    int length1=strlen(this->number);
    int length2=strlen(o1.number);
    int max;
    Big_number added_number;
    if (length1>length2){
      max=length1;
    }
    else max=length2;
    if (max==length1){
      added_number=*this;
      for (int i = max-1; i>=0 ; i--){
        int liczba =int(this -> number[length1-1]) -'0';
        int dodawana;
        if (length2>0){
          dodawana = int(o1.number[length2-1]) -'0';
        }
        else dodawana=0;
        liczba = liczba+dodawana;
        length1--;
        length2--;
        if (liczba>9){
          liczba = liczba-10;
          char cyfra_powrotna = char(liczba)+'0';
          if (i-1>=0){
            added_number.number[i] = cyfra_powrotna;
            added_number.number[i-1]++;
          }
          else{
            added_number.number[i] = cyfra_powrotna;
            for (int j=max; j>0;j--){
              added_number.number[j]=added_number.number[j-1];
            }
            added_number.number[0]='1';
          }
        }
        else{
          char cyfra_powrotna = char(liczba)+'0';
          added_number.number[i]=cyfra_powrotna;
        }
      }
    }
    if (max==length2 && length1!=length2){
      added_number=o1;
      for (int i = max-1; i>=0 ; i--){
        int liczba =int(o1.number[length2-1]) -'0';
        int dodawana;
        if (length2>0){
          dodawana = int(this->number[length1-1]) -'0';
        }
        else dodawana=0;
        liczba = liczba+dodawana;
        length1--;
        length2--;
        if (liczba>9){
          liczba = liczba-10;
          char cyfra_powrotna = char(liczba)+'0';
          if (i-1>=0){
            added_number.number[i] = cyfra_powrotna;
            added_number.number[i-1]++;
          }
          else{
            added_number.number[i] = cyfra_powrotna;
            for (int j=max; j>0;j--){
              added_number.number[j]=added_number.number[j-1];
            }
            added_number.number[0]='1';
          }
        }
        else{
          char cyfra_powrotna = char(liczba)+'0';
          added_number.number[i]=cyfra_powrotna;
        }
      }
    }
  return added_number;
  }

};//koniec Big_number

istream & operator >> (istream & s1, Big_number & o1){
  if (o1.number != NULL) delete o1.number;
  string input;
  s1 >> input;
  o1.number = new char[input.size()+1];
  for (int i=0;i<input.size()+1;i++){
    o1.number[i]=input[i];
  }
  o1.number[input.size()+1]='\0';
  return s1;
}

ostream & operator <<(ostream & s1, Big_number & o1){
  for (int i = 0; i < strlen(o1.number); i++){
    s1 << o1.number[i];
  }
  s1 << endl;
  return s1;
}

int main(){
  Big_number a, b, c;
  cin >> a;
  cin >> b;
  cout <<"a= "<< a <<"b= "  <<b;
  c=a;
  cout <<"c= "<< c <<"a= "<<a;
  c=a+b;
  cout <<"c=a+b= " <<c;
  return 0;
}