Frequency.java

public class Frequency {
    public static void main(String[] args) {
        //Initialise Array
        int[] arr = new int[]{1, 2, 8, 3, 2, 2, 2, 5, 1};
        //Array fr will store frequencies of element
        int[] fr = new int[arr.length];
        int visited = -1;
        for (int i = 0; i < arr.length; i++) {
            int count = 1;
            for (int j = i + 1; j < arr.length; j++) {
                if (arr[i] == arr[j]) {
                    count++;
                    //To avoid counting same element again
                    fr[j] = visited;
                }
            }
            if (fr[i] != visited)
                fr[i] = count;
        }
        System.out.println("Element Frequency :");
        for (int i = 0; i < fr.length; i++) {
            if (fr[i] != visited)
                System.out.println(" " + arr[i] + " = " + fr[i]);
        }
    }
}