[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.

同样是树的问题，直接递归解，就可以了。

 1 class Solution {
 2 public:
 3     bool isSameTree(TreeNode *p, TreeNode *q) {
 4         if(p == NULL && q==NULL)
 5             return true;
 6         if(p==NULL && q!=NULL || q==NULL && p!=NULL || p->val != q->val)
 7             return false;
 8         return isSameTree(p->right,q->right) && isSameTree(p->left,q->left);
 9     }
10 };