import java.util.*;
import java.io.*;
public class ArrayStuff{
private int[] a;
private Random r = new Random();
public ArrayStuff() {
a=new int[20];
for (int i=0;i<a.length;i++) {
a[i]=r.nextInt(100);
}
}
public String toString() {
return Arrays.toString(a);
}
// return the index of the max element
public int findMaxIndex() {
if (a==null || a.length==0)
return -1;
int maxi = 0;
for (int i=0;i<a.length;i++) {
if (a[i] > a[maxi])
maxi = i;
}
return maxi;
}
public int get(int n) {
if (n>=0 && n < a.length)
return a[n];
else
return -1;
}
public int find(int n) {
for (int i=0;i<a.length;i++) {
if (a[i]==n)
return i;
}
return -1;
}
// Homework 19 - Arrays 3 - in 3D
public double mean(){
double ans = 0;
for (int i=0; i<a.length;i++)
ans+=a[i];
return ans/a.length;
}
public double stddev(){
double mean = mean();
double total = 0;
for (int i=0; i<a.length; i++){
total+=Math.pow(mean-a[i],2);
}
return Math.pow(total/a.length,0.5);
}
}