#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>      // per il seed

int main() {
  float x, y, A;
  int N;

  time_t t;
  unsigned RandomSeed;
  
  printf("Dai il nr di punti\n");
  scanf("%d", &N);
  printf("N = %d\n", N);

  //   RandomSeed = 12345;
  RandomSeed = (unsigned) time(&t);
  srand( RandomSeed );

  int nIN = 0; 
  for (int i=0; i < (N); i++) {
    x = (float) rand() / (float) RAND_MAX;
    y = (float) rand() / (float) RAND_MAX;
    if( (x*x + y*y) <= 1. ) nIN += 1;
  }
  printf("nIN = %d \n", nIN);
  
  A = (float) nIN / N;
  
  printf("Area = %f (esatta %f)\n", A, acos(-1)/4.);
  puts("\nStima di pi greco");
  printf("Dall'area: %f\n", 4 * A);
  
  return 0;
}