题解 | #序列化二叉树#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param root TreeNode类 
 * @return char字符型一维数组
 */
void TreeToStr(struct TreeNode* Node, char* str, int* cur) {
    // 如果是空节点，我们用#号表示。
    if(Node == NULL) {
        (str)[*cur] = '#';
        (*cur)++;
        (str)[*cur] = ',';
        (*cur)++;
        return;
    } else {
        if(Node->val > 99) {
            (str)[*cur] = '1';
            (*cur)++;
            (str)[*cur] = Node->val / 10 % 10 + 48;
            (*cur)++;
            (str)[*cur] = Node->val % 10 + 48;
            (*cur)++;
        } else if(Node->val > 9) {
            (str)[*cur] = Node->val / 10 % 10 + 48;
            (*cur)++;
            (str)[*cur] = Node->val % 10 + 48;
            (*cur)++;
        } else {
            (str)[*cur] = Node->val + 48;
            (*cur)++;
        }
        (str)[*cur] = ',';
        (*cur)++;
        TreeToStr(Node->left, str, cur);
        TreeToStr(Node->right, str, cur);
    }
}

char* Serialize(struct TreeNode* root ) {
    // write code here
    char* str = (char*)malloc(500 * sizeof(char));
    int cur = 0;
    TreeToStr(root, str, &cur);
    str[cur] = '\0';
    printf("%s\n", str);
    return str;
}
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param str char字符型一维数组 
 * @return TreeNode类
 */
struct TreeNode* StrToTree(char* str, int* cur) {
    if((*(str + (*cur))) == '#') {
        (*cur) += 2;
        return NULL;
    }
    struct TreeNode *Node = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    Node->val = 0;
    while(*(str + (*cur)) != ',') {
        Node->val = (Node->val * 10) + (*(str + (*cur))) - 48;
        (*cur)++;
    }
    (*cur)++;
    printf("%d", (*cur));
    printf("%c", (*(str + (*cur))));
    Node->left = NULL;
    Node->right = NULL;
    Node->left = StrToTree(str, cur);
    Node->right = StrToTree(str, cur);
    return Node;
}

struct TreeNode* Deserialize(char* str ) {
    // write code here
    struct TreeNode* root = NULL;
    int cur = 0;
    root = StrToTree(str, &cur);
    return root;
}