same-tree——比较两个二叉树是否相同

Posted 2020-09-23 鸭子船长

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.

 

思路同比较二叉树是否对称，使用递归的方法

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     bool isSameTree(TreeNode *p, TreeNode *q) {
13         if(p==NULL&&q==NULL) return true;
14         if(p==NULL||q==NULL) return false;
15         if(p->val!=q->val) return false;
16         return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);
17     }
18 };