Z1

package com.company;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class TaskOne {
    public static void main(String[] args) {
        solution("zyzyzyz");
    }
    public static int solution(String S) {
        List<Integer> wordsLength = new ArrayList<>();
        boolean foundUnique = false;
            for(int j=1; j<S.length(); j++) {
                for (int i = 0; i < S.length()-j; i++) {
                    String tempWord = S;
                    String subword = S.substring(i, i+j);
                    if(isMoreThanOneOccurence(S, subword)){
                        wordsLength.add(subword.length());
                    }
                }
            }
            if(wordsLength.isEmpty()) {
                return S.length();
            }
        return Collections.min(wordsLength);
    }
    public static boolean isMoreThanOneOccurence(String s, String subword) {
        int counter = 0;
            for(int i=0; i<=s.length()-subword.length();i++) {
                if(s.substring(i, i+subword.length()).equals(subword)) {
                    counter++;
                }
            }
        return counter<2;
    }
}