Untitled

package lab2;

import java.util.Random;

/**
 *
 * @author James Valente
 */
public class Randmax {
    /*Because every java app needs main()*/

    /**
     *
     * @param args
     */
    public static void main(String[] args) {
        long startTime, endTime;
        int[] dummyArray;
        int maximum;
        double bigO;
        int sizes[] = {10, 100, 500, 1000, 5000, 10000, 50000, 100000, 1000000, 2000000, 5000000, 10000000};
        /*Time for output*/
        System.out.printf("%-10s   %-8s   %-8s   %-8s\n", "Size", "Max", "Runtime (ns)", "Big-O"); //Header part 1
        System.out.printf("%-10s   %-8s   %-8s   %-8s\n", "--------", "--------", "-----------", "--------"); //Header part 2
        String specify = "%-10s   %-8d   %-8d ns   %-8f\n"; //Output format specifer.
        /*Now begins the point at which I must output each max and its runtime.*/
        for (int i = 0; i < sizes.length; i++) {
            dummyArray = populate(sizes[i]);
            startTime = System.nanoTime();
            maximum = findMax(dummyArray);
            endTime = System.nanoTime() - startTime;
            bigO = (double)endTime/(double)sizes[i];
            System.out.printf(specify, sizes[i], maximum, endTime, bigO);
        }
    }
    /*Some method that most likely exists as a java builtin.*/

    /**
     *
     * @param arr Array to find max
     * @return  Max value of array
     */
    public static int findMax(int[] arr) {
        int max = arr[0]; /*Value was zero
         * Negatives could cause issues
         * Here's my fix for that
         */
        for (int i = 1; i < arr.length; i++) {
            if (arr[i] > max) {
                max = arr[i]; //Highlander style: there can be only one.
            }
        }
        return max;
    }
    /*With 9+ arrays being populated, creating a function is much more efficient*/

    /**
     *
     * @param n Size of Array
     * @return Randomly populated array of size n
     */
    public static int[] populate(int n) {
        int array[] = new int[n];
        Random randGen = new Random(); //Yay OOP
        int seed = 10000000; //uh sure
        for (int i = 0; i < array.length; i++) {
            int phobos = randGen.nextInt(seed); //Okay make a random
            int deimos = randGen.nextInt(seed / 2); //You too, pick a random.
            array[i] = deimos - phobos; //Do mathy things to be SUPER RANDOM
        }
        return array;
    }
}