AcadEx: Expected Mean of a Dice Output - ITA

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#define NMAX 1000000
#define MaxFacce 100

int getInt (char*,int,int);
double mediaCamp (int*,int);
double devStd (int*,double,int);

int main () {
  int x, i, c, j, dati[NMAX], N, facce;
  double media, dev;
  srand48(time(0));
  facce = getInt("Facce del dado",1,MaxFacce);
  c = getInt("Inserire numero da attendere",1,facce);
  N = getInt("Numero di prove",1,NMAX);
  for(i=0;i<N;i++) {
    j=0;
    do {
      x = (lrand48()%facce)+1;
      j++;
    } while(x!=c);
    *(dati+i) = j;
  }
  media = mediaCamp(dati,N);
  dev = devStd(dati,media,N);
  printf("Attesa: %lf +- %lf\n",media,3*dev/N);
  return 0;
}

int getInt (char*mess,int min, int max) {
  int out;
  do {
    printf("%s tra %d e %d: ",mess,min,max);
    scanf("%d",&out);
  } while(out<min||out>max);
  return out;
}

double mediaCamp (int*array,int len) {
  int i;
  double out=0;
  for (i=0;i<len;i++) {
    out+= *(array+i);
  }
  return out/len;
}

double devStd (int*array,double in, int len) {
  int i;
  double out=0;
  for (i=0;i<len;i++) {
    out+= pow(*(array+i),2);
  }
  return sqrt(out-pow(in,2));
}