ColourFull Number - https://www.interviewbit.com/problems/colorful-number/

colourful.java

public class Solution {
    public int colorful(int a) {
        String input = String.valueOf(a);
        int N = input.length();

        HashSet<Long> productOf = new HashSet<>();

        List<String> results = new ArrayList<>();
        for (int m = 1; m <= N; m++) {
            for (int i = 0; i + m <= N; i++) {
                results.add(input.substring(i, i + m));
            }
        }

        for (String str : results) {

            long product = 1;
            for (int i = 0; i < str.length(); i++) {
                product = product * Long.valueOf(str.substring(i, i + 1));
            }
            if (productOf.contains(product))
                return 0;

            productOf.add(product);
        }

        return 1;
    }
}