题目描述
请实现两个函数,分别用来序列化和反序列化二叉树
/*
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
TreeNode(int x) :
val(x), left(NULL), right(NULL) {
}
};
*/
class Solution {
public:
//按DFS顺序把树的值打印出来,'#'代表空,反序列也就可以按相同的方法得到
char* Serialize(TreeNode *root) {
if (root == nullptr)
return nullptr;
stringstream ss;
SerializeCore(root, ss);
string s = ss.str();
char *ret = new char[s.size() + 1];
for (int i = 0; i < s.size(); ++i)
{
ret[i] = s[i];
}
ret[s.size()] = '\0';
return ret;
}
TreeNode* Deserialize(char *str) {
if (str == nullptr)
return nullptr;
TreeNode *root;
DeserializeCore(&str, &root);
return root;
}
private:
void SerializeCore(TreeNode *root, stringstream &ss)
{
if (root == nullptr)
ss << "#,";
else
{
ss << root->val << ",";
SerializeCore(root->left, ss);
SerializeCore(root->right, ss);
}
}
void DeserializeCore(char **str, TreeNode **p)
{
if ((*str)[0] == '\0')
{
*p = nullptr;
return;
}
else if((*str)[0] == '#')
{
*p = nullptr;
(*str) += 2;
return;
}
else
{
int x = 0;
while ((**str) >= '0' && (**str) <= '9')
{
x = x*10 + (**str)-'0';
++(*str);
}
*p = new TreeNode(x);
++(*str);
DeserializeCore(str, &((*p)->left));
DeserializeCore(str, &((*p)->right));
}
}
};