ArrayStuff.java

import java.io.*;
import java.util.*;

public class ArrayStuff {
    private int[] a;
    private Random r;

    public ArrayStuff() {
	r = new Random();
	a = new int[20];
	for (int i=0;i<a.length;i++) 
	    a[i]=r.nextInt(100);
    }

	public ArrayStuff(int[] p) {
		a = p;
	}
    public String toString() {
	return Arrays.toString(a);
    }

    public int get(int n) {
	return a[n];
    }

    public int findMaxIndex() {
	int maxi = 0;
	for (int i =0 ; i < a.length;i++) {
	    if (a[i]>a[maxi]) 
		maxi = i;
	}
	return maxi;
    }

    public int find(int n) {
	for (int i=0;i<a.length;i++) {
	    if (a[i]==n)
		return i;
	}
	return -1;
    }
	
	public double mean() {
		int sum = 0;
		for (int i = 0; i < a.length; i++) {
			sum += get(i);
		}
		return sum / a.length;
	}
	
	public double stddev() {
		double totalDS = 0;
		double avrg = mean();
		for (int i = 0; i < a.length;i++) {
			double p = (get(i) - avrg);
			totalDS += p * p;
		}
		return Math.sqrt(totalDS / a.length);
	}
}