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() {
	double sum = 0.0;
	double m;
	for (int i = 0;i<a.length;i++) {
	    sum = sum + a[i];
	}
	m = ((double)(sum)) / a.length;
	return m;
    }

    public double stddev() {
	double mean;
	double sum = 0.0;
	for (int i=0;i<a.length;i++) {
	    sum = sum + a[i];
	}
	mean = (double)(sum) / a.length;
	double newsum = 0.0;
	double newmean, answer;
	double[] result = new double[a.length];
	for (int i =0;i<a.length;i++) {
	    result[i] = (a[i] - mean)*(a[i] - mean);
	}
	for (int i=0;i<a.length;i++) {
	    newsum = newsum + result[i];
	}
	newmean = newsum / result.length;
	answer = Math.sqrt(newmean);
	return answer;
    }
}