leetCode(14):Invert Binary Tree and Same Tree

反转二叉树：

/**
 * 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:
    TreeNode* invertTree(TreeNode* root) {
        if(root==NULL)
    		return NULL;
    	if(root->left==NULL && root->right==NULL)
    		return root;

    	TreeNode* tmpNode=root->right;
    	root->right=root->left;
    	root->left=tmpNode;
    	if(root->left)
    	{
    		root->left=invertTree(root->left);
    	}
    	if(root->right)
    	{
    		root->right=invertTree(root->right);
    	}
    	return root;
    }
};

判断是否是相同二叉树：

/**
 * 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 && q==NULL)
    		return true;
    	if(p==NULL || q==NULL)
    		return false;

    	if(p->val==q->val)
    	{
    		return isSameTree(p->left,q->left) && isSameTree(p->right,q->right);
    	}
    	else
    	{
    		return false;
    	}
    }
};