LeetCode : 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.

哈哈，写这种代码还是轻车熟路的。

/** * Definition for binary tree * 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) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        if(p == NULL && q == NULL) return true;        if(p == NULL || q == NULL) return false;        if(p->val != q->val) return false;        return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);    }};