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; } public double mean(){ double x = 0; for (int i=0; i < a.length; i = i + 1){ x = x + a[i]; } x = x/a.length; return x; } public double stddev(){ double x = 0; double y = mean(); for (int i = 0; i < a.length; i = i + 1){ x = x + ((a[i] - y) * (a[i] - y)); } x = x/a.length; x = Math.sqrt(x); return x; } }