MostFrequentNumbers.java

import java.util.Random;
import java.util.Arrays;

public class MostFrequentNumbers {

    /* Sometimes there is more than one value that occurs most often in a random array */

    static final int N = 40;    // number of numbers in array
    static final int MAX = 4 * N;   // range is zero to MAX inclusive

    static int[] counts = new int[MAX+1]; // number of occurances for each number

    public static int getMaxCount(int[] n) {
    // determine the maximum occurances of any number in array
        int maxCount = 0; // count of most occurances
        for (int i=0; i<n.length; i++) {
            counts[n[i]]++;
            if (maxCount<counts[n[i]]) {
                maxCount = counts[n[i]];
            } // end if
        } // end for
        return maxCount;
    } // end getMaxCount()

    public static void printMostFrequent(int[] n) {
    // print the numbers which appear most often

        int mostTimes = getMaxCount(n);
        boolean[] printed = new boolean[MAX+1]; // so that numbers are only printed once

        for (int i=0; i<n.length; i++) {
            if (counts[n[i]]==mostTimes && !printed[n[i]]) {
                System.out.print(n[i]+" ");
                printed[n[i]]= true; // so we don't print it again
            } // end if
        } // end for
        System.out.println();
    } // end printMostFrequent()

    public static void main(String[] args) {
        Random ran = new Random();
        int[] A = new int[N];

        // populate array with random numbers
        for (int i=0; i<N; i++) {
            A[i] = ran.nextInt(MAX+1);
        } // for

        Arrays.sort(A);
        System.out.println( Arrays.toString(A));

        System.out.print("Most frequently occuring number(s): ");
        printMostFrequent(A);
    } // main()

} // class MostFrequentNumbers