Leetcode 100. Same Tree

分析

我的代码

/**
* 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 == NULL)   //p为NULL
{
if(q == NULL) return true;
else if(q != NULL) return false;
}

if(q == NULL)   //q为NULL
{
if(p == NULL) return true;
else if(p != NULL) return false;
}

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

return true;

}
};