目前最火最热门的python经典编程题之2

/* struct TreeNode { int val; struct TreeNode *left; struct TreeNode *right; TreeNode(int x) : val(x), left(NULL), right(NULL) { } }; */ class Solution {   public:     char* Serialize(TreeNode *root) {        if(root == NULL)            return NULL;         string str;         Serialize(root, str);         char *ret = new char[str.length() + 1];         int i;         for(i = 0; i < str.length(); i++){             ret[i] = str[i];         }         ret[i] = '\0';         return ret;     }     void Serialize(TreeNode *root, string& str){         if(root == NULL){             str += '#';             return ;         }         string r = to_string(root->val);         str += r;         str += ',';         Serialize(root->left, str);         Serialize(root->right, str);     }           TreeNode* Deserialize(char *str) {         if(str == NULL)             return NULL;         TreeNode *ret = Deserialize(&str);           return ret;     }     TreeNode* Deserialize(char **str){//由于递归时，会不断的向后读取字符串         if(**str == '#'){  //所以一定要用**str,             ++(*str);         //以保证得到递归后指针str指向未被读取的字符             return NULL;         }         int num = 0;         while(**str != '\0' && **str != ','){             num = num*10 + ((**str) - '0');             ++(*str);         }         TreeNode *root = new TreeNode(num);         if(**str == '\0')             return root;         else             (*str)++;         root->left = Deserialize(str);         root->right = Deserialize(str);         return root;     } };