找两个和为目标值且不重叠的子数组

/*
 * Given an integer array arr and an integer target,
 * find two non-overlapping subarrays such that their sums are equal to target.
 * Return the minimum sum of their lengths. If no such subarrays exist, return -1.
 * Java Stream API is not well suited for this type of problem due to its complex state management.
 * This implementation is provided for completeness but uses traditional loops internally.
 */
public class Solution {
    public int minSumOfLengths(int[] arr, int target) {
        int n = arr.length;
        int[] prefixMin = new int[n];
        Arrays.fill(prefixMin, Integer.MAX_VALUE);
        int sum = 0;
        int minLen = Integer.MAX_VALUE;
        int result = Integer.MAX_VALUE;
        Map<Integer, Integer> map = new HashMap<>();
        map.put(0, -1);
        IntStream.range(0, n).forEach(i -> {
            sum += arr[i];
            if (map.containsKey(sum - target)) {
                int start = map.get(sum - target) + 1;
                int len = i - start + 1;
                if (start > 0 && prefixMin[start - 1] != Integer.MAX_VALUE) {
                    result = Math.min(result, len + prefixMin[start - 1]);
                }
                minLen = Math.min(minLen, len);
            }
            prefixMin[i] = minLen;
            map.put(sum, i);
        });
        return result == Integer.MAX_VALUE ? -1 : result;
    }
}