#include <iostream>
#include <ctime>
#include <cstdlib>
#include <cmath>
#include <omp.h>
 int N=0;
using namespace std;

int circle( int chunk) { // ôóíêöèÿ, êîòîðàÿ ñ÷èòàåò äëÿ êàæäãî áëîêà êîë-âî òî÷åê â êðóãå
  int n = chunk;
  srand( time (NULL));
  double x,r;
  double y;
  int Nt=0;
	  for( int i = 0; i < n; i++ ){ //  öèêë äëÿ ïîäñ÷åòà â äàííîì áëîêå êîë-âà ïîïàâøèõ òî÷åê
	    x = (double)rand()*2/RAND_MAX - 1; // ãåíåðàöèÿ êîîðäèíàò
	    y  = (double)rand()*2/RAND_MAX - 1;
	    r = sqrt (x*x+y*y);
	      if(r < 1) Nt++; // ïðîâåðêà óñëîâèÿ
	  }
    return Nt;
}

int main(){
  long int Tsamples=1e6; //  îáùåå êîë-âî ýêñï. òî÷åê
  int omp_get_num_threads(void);
  int num_of_Threads; // çàäàåì êîë-âî ïîòîêîâ
  int chunk;  //  êîë-âî áëîêîâ
  int i=0;
  #pragma omp parallel
   num_of_Threads= omp_get_num_threads();
   chunk = Tsamples/num_of_Threads;

  #pragma omp for schedule(static,chunk)   private (i) reduction(+:N)
    for ( i=0; i < num_of_Threads; i++ ) { // öèêë äëÿ âûçîâà ôóíêöèè äëÿ êàæîãî áëîêà è ñóììèðîâàíèÿ ðåçóëüòàòîâ
     N+= circle( chunk );
     }
  double pi;
  pi = 4 * N / Tsamples; // âû÷èñëÿåì  ÷èñëî Ïè ïî ôîðìóëå  Ìîíòå-Êàðëî
  cout<<"N= "<< N<< "pi =  " << pi;
  return 0;
}