BigNum.cpp

#include <iostream>
#include <cstdio>
#include <string>
#include <unistd.h>
#include <windows.h>
#include "stdafx.h"
/*
 * bigNum v0.2. - operacje na DUZYCH liczbach
 *
 * author: Jakub Ziółkowski (jakub.ziolkowski@hotmail.com)
 */
class bigNum {
    public:
        std::string z; /* Wynik */
        unsigned char r; /* Reszta */
        double time; /* Licznik czasu obliczen */

        void clean(){ this->z = ""; this->r = 0; }; /* Czysci pamiec */

        /* czas CPU w usec */
        double timer(){
            timeval t; gettimeofday(&t, NULL);
            return (double)t.tv_sec+(t.tv_usec/1000000.0);
        }

        /* dodawanie 2ch liczb calkowitych dodatnich */
        std::string plus(const std::string& a, const std::string& b) {
            this->clean();
            double start = timer();

            int a_s = a.size(), b_s = b.size(),
            limit = a_s > b_s ? a_s : b_s,
            mov_a = a_s-1, mov_b = b_s-1;

            this->z.resize(limit + 1);
            for (int i = limit; i >= 0; i--){
                if (mov_a >= 0)this->r += a[mov_a--] - '0';
                if (mov_b >= 0)this->r += b[mov_b--] - '0';
                this->z[i] = this->r % 10 + '0';
                this->r /= 10;
            }
            this->time += this->timer()-start;
            return (this->z[0] == '0')?this->z.substr(1):this->z;
        }

        /* mnozenie 2ch liczb calkowitych dodatnich */
        std::string mul(const std::string& a, const std::string& b)
        {
            this->clean();
            double start = timer();
            int a_s = a.size(), b_s = b.size(),
            o_l = a_s + b_s;//,
           // mov_a = a_s - 1, mov_b = b_s - 1;

            this->z.resize(o_l);
            for (int i = 0; i < o_l; i++) this->z[i] = '0';
            for (int i = a_s - 1; i >=0; i--) {
                this->r = 0;
                for (int j = b_s - 1; j >= 0; j--){
                  this->r += this->z[i + j + 1] - '0';
                  this->r += (a[i] - '0') * (b[j] - '0');
                  this->z[i + j + 1] = this->r % 10 + '0';
                  this->r /= 10;
                }
                this->r += this->z[i] - '0';
                this->z[i] = this->r % 10 + '0';
            }
            this->time += this->timer()-start;
            return (this->z[0] == '0')?this->z.substr(1):this->z;
        }

        /* Potega */
        std::string pow(const std::string a, long long int x){
            std::string out = "1";
            while(x--) out = this->mul(out,a);
            return out;
        }

        /* Silnia z liczby calkowitej */
        std::string silnia(int n){
            std::string _r = "1", _m = "2";
            for (int i = 2; i <= n; i++) {
                _r = this->mul(_r, _m);
                _m = this->plus(_m, "1");
                if(i%100 == 0) std::cout << "n~=" <<  i << "\r"; // DEBUG
            }
            return _r;
        }
};

int main(){

   int x;
    bigNum* handler = new bigNum();

     std::string WYNIK;
    printf("* Silnia * (N! = x),\nn=");
    //std::cout << "n! = x podaj n\r";
    std::cin >> x;
	WYNIK = handler->silnia(x);
    std::cout << WYNIK << std::endl;
    handler->clean();
    printf("\n %d cyfr\nCzas procesora): %.6lf\n",WYNIK.size(), handler->time);
    WYNIK = "";
    std::string a,b;
    printf("* Iloczyn (AxB = x),\nA=");
    std::cin >> a;
    printf("B=");
    std::cin >> b;
	WYNIK = handler->mul(a,b);
	std::cout << WYNIK << std::endl;

    delete handler;
}