//Paragwgh tyxaiwn arithmwn kanonikhs katanomhs me Monte-Carlo methodo.
//To aoristo oloklhrwma ths f(x):Gauss den yparxei kai efarmozw monte-carlo.

#include <cstdlib>
#include <cmath>
#include <time.h>
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main()
{   
	const int a=0,b=1000;
	double x,y,f,m,s;
	int i=0,j;
	cout<<"\n";
	cout<<" PARGWGH TYXAIWN ARITHMWN KANONIKHS KATANOMHS "<<"\n\n";//Mporeis na baleis pollapla \n
	cout<<"\tDwse thesh koryfhs:"<<"\n";//To \t afhnei proka8orismeno keno
	cin>>m;
	cout<<"\tDwse diaspora:"<<"\n";
	cin>>s;
	cout<<"\tPlhthos tyxaiwn arithmwn:"<<"\n";
	cin>>j;
	cout<<"\n"; 
	time_t seconds; 
	time(&seconds); 
	srand((unsigned int) seconds);

	//Proetoimasia arxeiou e3odou. Ta dedomena 8a tupw8oune se ena arxeio "data.csv"
	//mesa ston fakelo pou uparxei to .exe sou.
	string outputname = "data.csv";
	ofstream file;
	if (outputname != "")
	{
		if (outputname.rfind(".csv") == -1)
			outputname += ".csv";
		file.open(outputname.c_str());
		if (!file)
		{
			cerr << "Sfalma: De mporw na anoi3w auto to arxeio (" << outputname << ")." << endl;
			exit(-1);
		}
	}
	char* buffer = 0;
	buffer = new char[2000];
	//Telos proetoimasia arxeiou e3odou

	while(i<j)
	{
		//tha paraksw tyxaious omoiomorfhs katanomhs sto (m-4s,m+4s) 
		x=(float)(rand()%(b-a)+a)/1000.0;//x :tyxaio omoiomorfhs katanomhs sto (0,1)
		x=(x-0.5)*8*s+m;//to (0,1) metaferetai sto (-0.5,0.5) kai diasteletai kata 
		// 8 diaspores ,meta metaferetai gyro apo thn mesh timh m.
		//Grafw thn f(x):Gauss synarthsei twn m,s  
		f=(pow(2.718281828,-(pow((x-m)/s,2))/2)) / (s*(sqrt(2*3.141592654)));
		//Zari... y tyxaio omoiomorfhs katanomhs sto (o , f max)
		y=(float)(rand()%(b-a)+a)/1000.0;  //y sto (0,1)
		y=y/(s*(sqrt(2*3.1415926)));       //y sto (0 , f max)
		if(f>=y) 
		{
			cout<<" "<<x<<"\n";i++;
			sprintf(buffer, "%f", x);
			char* p = buffer; while(*p) {if (*p == '.') *p = ','; p++;}
			if (file) file << buffer << endl;
		}   
	}

	//Kleinei to arxeio
	delete[] buffer;
	if (file)
		file.close();
	//arxeio papala
	return 0;
}