LeetCode - Same Tree

题目描述：

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.

同时遍历p、q两个树，如果出现p、q两个树结构不同或者存在节点的值有不同，那么说明不是相同的树，遍历的过程可以通过的递归来实现。

class Solution {public:    bool isSameTree(TreeNode* p, TreeNode* q) {    if(p==NULL&&q==NULL)    return true;    else if((p==NULL&&q!=NULL)||(p!=NULL&&q==NULL))        return false;        else if(p->val!=q->val)        return false;        return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);    }};