leetcode 100

100. Same Tree

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.

判断两个二叉树是否相同，结点的值和结构都相同。

采用递归来实现。

代码如下：

 /**
  * Definition for a binary tree node.
  * struct TreeNode {
  *     int val;
  *     TreeNode *left;
  *     TreeNode *right;
  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
  * };
  */
 class Solution {
 public:
     bool isSameTree(TreeNode* p, TreeNode* q) {
         if(!p && !q)
         {
             return true;
         }
         if(p && q && p->val == q->val)
         {
             if(isSameTree(p->left, q->left))
             {
                 if(isSameTree(p->right, q->right))
                 {
                     return true;
                 }
             }
         }
         return false;
     }
 };