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.

       递归DFS遍历两棵树，在相同的位置上，如果节点有一个为NULL或者两个节点的值不相同，则返回false，遍历完返回true.

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