递归-二叉搜索树-leetcode98验证二叉搜索树

//leetcode submit region begin(Prohibit modification and deletion)/** * Definition for a binary tree node. * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode() {} *     TreeNode(int val) { this.val = val; } *     TreeNode(int val, TreeNode left, TreeNode right) { *         this.val = val; *         this.left = left; *         this.right = right; *     } * } */  思路：搜索树，左子树小于根节点，根据这一特点，右子树大于根节点 class Solution {    public boolean isValidBST(TreeNode root) {        return isValid(root,null,null);    }    boolean isValid(TreeNode root,TreeNode min,TreeNode max){        if(root==null){            return true ;        }        ///节点左子树只包含 小于 当前节点的数量。        if(min!        if(min!=null && min.val>=root.val){            return false;        }        ///节点的右子树只包括 大于 当前节点的数量。        if(max!=null && max.val<=root.val){            return false;        }        return isValid(root.left,min,root)&&isValid(root.right,root,max);    }}//leetcode submit region end(Prohibit modification and deletion)

不爱世间浮华，不写红尘纷扰