Java + Count duplicates from int array without using any Collection or another intermediate Array

Question

As a part of the Java interview question paper I have got following issue to solve. But I am bit wonder whether how can I implement it without any Collection or intermediate

Answer 1

    int numbers[]={7,2,6,1,4,7,4,5,4,7,7,3, 1};
    String temp="";
    int count=0;
    Arrays.sort(numbers);

    for (int i = 0; i < numbers.length; i++) {

        boolean duplicate = false;
        for(int j = 0; j < numbers.length; j++) {
            if ((i != j) && numbers[i] == numbers[j]) {
                duplicate = true;
            }
        }

        if (duplicate) {
            if(!temp.contains(""+numbers[i]))
            {
            temp+=numbers[i]+", ";//adding a number if its duplicate
            count++;//counting unique duplicate number
            }
            System.out.print(numbers[i] + " ");
        }
    }
    System.out.println("\nDuplicates are: "+temp+" count: "+count);

Output:

 Duplicates are: 1, 4, 7,  count: 3