学步园

http://oj.leetcode.com/problems/same-tree/

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