#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

int main (int argc, char *argv[]){
  // quanti lanci?
  int maxIter=1000;
  // la prendo anche come argomento dalla command line
  if (argc==2) {
    maxIter=atoi(argv[1]);
  }

  // initialize rand to actual time
  srand((unsigned int)time(0));

  // get a random point x and y (0-1]
  int inside=0;
  for (int i=0 ; i<maxIter ; ++i) {
    double x = (1.*rand()/RAND_MAX);
    double y = (1.*rand()/RAND_MAX);
    if ((x*x+y*y)<=1) inside++;
  }

  cout << "Pi = " << (4.*inside)/maxIter << endl;

  return 0;
}