数组是否表示某二叉树的前序遍历

/*
 * LeetCode 2764: Verify if an array represents the preorder traversal of a binary tree
 * 
 * Approach using Java Streams:
 * While Java Streams are more suited for functional operations on collections,
 * this problem requires state tracking (lowerBound) and a stack for validation.
 * Hence, using streams here would be less intuitive and more convoluted.
 * We can use a stream to iterate over the array, but state changes make it impractical.
 */

import java.util.Stack;
import java.util.Arrays;

public class Solution {
    public boolean verifyPreorder(int[] preorder) {
        Stack<Integer> stack = new Stack<>();
        int[] lowerBound = {Integer.MIN_VALUE};
        return Arrays.stream(preorder).allMatch(value -> {
            if (value < lowerBound[0]) {
                return false;
            }
            while (!stack.isEmpty() && value > stack.peek()) {
                lowerBound[0] = stack.pop();
            }
            stack.push(value);
            return true;
        });
    }
}