#include <iostream>
#include <cstdlib> 
#include <ctime>
using namespace std;

int main()
{
  const int NUMBER_OF_TRIALS = 1000000;
  int numberOfHits = 0;
  srand(time(0));

  for (int i = 0; i < NUMBER_OF_TRIALS; i++)
  {
    double x = rand() * 2.0 / RAND_MAX - 1;
    double y = rand() * 2.0 / RAND_MAX - 1;
    if (x * x + y * y <= 1)
      numberOfHits++;
  }

  double pi = 4.0 * numberOfHits / NUMBER_OF_TRIALS;
  cout << "PI is " << pi << endl;

  return 0;
}