Find max length of elements from an array

learner :

I am working on a program where I need to find out the maximum chain that can be formed from a given array.

Example:

Let's say input is :

Arr[0] = 5
Arr[1] = 4
Arr[2] = 0
Arr[3] = 3
Arr[4] = 1
Arr[5] = 6
Arr[6] = 2

Now if I take the array index and the corresponding value the possible max chain I can form is

index 0 with value 5 --> index 5 with value 6 --> index 6 with value 2 --> index 2 with value 0. This cycle repeats so this is my maximum chain i can form using this array

Here is my code:

public static int getMax(int[] nums) {
        int result = 0;
        for (int i = 0; i < nums.length; i++) {
            List<Integer> list = new ArrayList<>();
            list.add(i);
            int temp = i;
            while (true) {
                int next = nums[temp];
                if (list.contains(next)) {
                    break;
                } else {
                    list.add(next);
                    temp = next;
                }
            }
            result = Math.max(result, list.size());
        }
        return result;
    }

I have come up with above logic but I see that in my code I am trying to find multiple chains of the same type.

It means if I print my list it has these values:

[0, 5, 6, 2]
[1, 4]
[2, 0, 5, 6]
[3]
[4, 1]
[5, 6, 2, 0]
[6, 2, 0, 5]

Here 0,5,6,2 chain is repeated multiple times, is there a way to improve my code performance to avoid unnecessary similar loops like above.

Sandeepa :

You can put each values you get to an array by checking if that item is already contains in the array. Then when you iterate if you get a number in the array you filled, you can ignore that iteration by using continue