序列化二叉树

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

代码

/*
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) {//bfs
        string ans;
        if (root != NULL) {
            queue<TreeNode*> que;

            que.push(root);
            TreeNode* cur;
            while (!que.empty()) {
                cur = que.front();
                que.pop();
                if (cur == NULL) {
                    ans += '#';
                } else {
                    if (ans.size() > 0 && ans[ans.size() - 1] != ' ' && ans[ans.size() - 1] != '#') {
                        ans += ' ';
                    }
                    ans += to_string(cur->val);

                    que.push(cur->left);
                    que.push(cur->right);
                }
            }

        }
        char *result = new char[ans.size() + 1];
        for (int i = 0; i < ans.size(); ++i) {
            result[i] = ans[i];
        }
        result[ans.size()] = '\0';
        return result;

    }
    TreeNode* Deserialize(char *str) {//bfs
        TreeNode* root = NULL;
        if (str[0] != '\0') {
            queue<TreeNode*> que;
            int s = 0;
            root = newNode(str, s);
            que.push(root);
            TreeNode* cur;
            while (str[s] != '\0') {
                cur = que.front();
                que.pop();

                if (isdigit(str[s]) || str[s++] == ' ') {
                    TreeNode* left = newNode(str, s);
                    cur->left = left;
                    que.push(left);
                }

                if (str[s] != '\0' && (isdigit(str[s]) || str[s++] == ' ')) {
                    TreeNode* right = newNode(str, s);
                    cur->right = right;
                    que.push(right);
                }
            }

        }
        return root;
    }

    TreeNode* newNode(char *str, int &s) {
        string num;
        while (str[s] != '\0' && str[s] != ' ' && str[s] != '#') {
            num += str[s];
            ++s;
        }
        return new TreeNode(stoi(num));
    }
};