Verify Preorder Sequence in Binary Search Tree

一道很好的拓展题，对于follow up，我们之后继续看。

参考：点击打开链接

public class Solution {    public boolean verifyPreorder(int[] preorder) {        int min = Integer.MIN_VALUE;        Stack<Integer> stack = new Stack<>();        for (int i: preorder) {            if (i < min) {                return false;            }            while (!stack.isEmpty() && i > stack.peek()) {                min = stack.pop();            }            stack.push(i);        }        return true;    }}