Easy 20 Same Tree（100）

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.

Solution
深度优先遍历，左右子树和数据都要相同。

/** * 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 (!p&&!q);       }else{            return (p->val==q->val)&&isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);       }      }};