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 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 = sum + a[i];
	}
	return sum/a.length;
	}
	
	public double stddev() {
	double means = this.mean();
	double temp = 0;
	double newmeans = 0;
	
	for (int i = 0; i<a.length;i++) {
	temp = temp + (a[i] - means)*(a[i] - means);
	newmeans = temp/a.length;
	}
	
	
	return Math.sqrt(newmeans);
	}

}