统计好分割方案的数目

// Java solution using Streams
// Problem description: Given an array of positive integers, find the number of good split schemes. A good split scheme is defined as splitting the array into one or more continuous subarrays where no two subarrays contain the same number.
// Approach: We use Java Streams to handle data manipulation. We maintain sets for the left and right partitions and use sets to track unique elements. The process involves adjusting sets as we iterate through the array.

import java.util.*;
import java.util.stream.Collectors;

public class GoodSplitSchemesStream {
    public static int countGoodSplits(int[] nums) {
        final int MOD = 1000000007;
        Set<Integer> leftSet = new HashSet<>();
        Set<Integer> rightSet = Arrays.stream(nums).boxed().collect(Collectors.toSet());

        int goodSplits = 0;
        for (int num : nums) {
            leftSet.add(num);
            rightSet.remove(num);

            if (leftSet.size() == rightSet.size()) {
                goodSplits = (goodSplits + 1) % MOD;
            }
        }

        return goodSplits;
    }
}