二叉树的序列化和反序列化

#include <sstream>
#include <deque>
#include <string>
struct TreeNode {
	int val;
	TreeNode* left;
	TreeNode* right;
	TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};
using namespace std;
class Solution {
public:
	string serialize(TreeNode* root) {
		ostringstream os;
		deque<TreeNode*> deq;
		string res = "";
		if (!root)
			return res;
		deq.push_back(root);
		while (!deq.empty()) {
			TreeNode* tmp = deq.front();
			if (tmp) {
				os << tmp->val << " ";
				deq.push_back(tmp->left);
				deq.push_back(tmp->right);
			} else {
				os << "# ";
			}
			deq.pop_front();
		}
		return os.str();
	}
	TreeNode* deserialize(string data) {
		if (!data.size())
			return nullptr;
		istringstream is(data);
		deque<TreeNode*> deq;
		string val;
		is >> val;
		TreeNode* root = new TreeNode(stoi(val));
		TreeNode* cur = root;
		deq.push_back(root);
		while (!deq.empty()) {
			TreeNode* node = deq.front();
			deq.pop_front();
			is >> val;
			if (val != "#") {
				cur = new TreeNode(stoi(val));
				node->left = cur;
				deq.push_back(cur);
			}
			is >> val;
			if (val != "#") {
				cur = new TreeNode(stoi(val));
				node->right = cur;
				deq.push_back(cur);
			}
		}
		return root;
	}
};