Description
Given two binary trees, write a function to check if they are equal or not.
Two binary trees are considered equal if they are structurally identical and the nodes have the same value.
思路
题意:给出两棵二叉搜索树,判断这两棵二叉搜索树是否相同
题解:前序遍历+中序遍历或后序遍历+中序遍历可以完全确定一颗二叉搜索树(数据中第52组:[1,null,1] [1,1],此种写法挂在了这里);或者直接递归搜索的过程判断。
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if (p == null && q == null) return true; if (p == null || q == null) return false; if (p.val == q.val) return isSameTree(p.left,q.left) && isSameTree(p.right,q.right); else return false; } }