#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<math.h>

#define PI  3.14159265359

double f(double x)
{
   return sin(x);
}

double mc1(double a, double b, int n, double (*func)(double))
{
   double s = 0.0, x, fx;
   int j;

   for (j=0; j < n; j++){
      x = a + (b-a) * ((double)rand() / RAND_MAX);
      s += (*func)(x);
    }
   s = (b - a) * s / n;
   return s;
}

int main()
{
   double a = 0.0, b = PI/2.0, s;
   int n;

   printf("Ile losowan n=");
   scanf("%d", &n);
   
   srand(time(0));

   s = mc1(a, b, n, f);
   printf("n=%6d s=%10.6f \n", n, s );
}