拆分字符串使唯一子字符串的数目最大

// Java Stream solution with detailed explanation
// Streams are not particularly well-suited for this problem as it involves backtracking, but we'll use them for set operations
// The solution is essentially the same as the basic Java approach but with a stream twist

import java.util.HashSet;
import java.util.Set;
import java.util.stream.IntStream;

public class SolutionStream {
    public int maxUniqueSplit(String s) {
        return backtrack(s, 0, new HashSet<>());
    }

    private int backtrack(String s, int start, Set<String> seen) {
        if (start == s.length()) {
            return seen.size();
        }
        return IntStream.range(start + 1, s.length() + 1)
                .map(end -> {
                    String substring = s.substring(start, end);
                    if (!seen.contains(substring)) {
                        seen.add(substring);
                        int maxCount = Math.max(seen.size(), backtrack(s, end, seen));
                        seen.remove(substring);
                        return maxCount;
                    }
                    return seen.size();
                }).max().orElse(seen.size());
    }
}