Design Linked List LeetCode solution in C++

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class MyLinkedList {
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  struct Node {
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    int val;
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    Node *next, *prev;
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    Node(int x) {
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      val = x, next = prev = NULL;
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    }
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  };
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  Node *head;
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  int size;
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 public:
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  MyLinkedList() {
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    head = NULL;
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    size = 0;
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  }
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  int get(int index) {
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    if (index >= size or index < 0) return -1;
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    Node *ptr = head;
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    for (int i = 0; i < index; i++) ptr = ptr->next;
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    return ptr->val;
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  }
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  void addAtHead(int val) {
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    Node *newNode = new Node(val);
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    newNode->next = head;
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    if (head) head->prev = newNode;
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    head = newNode;
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    size++;
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  }
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  void addAtTail(int val) {
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    addAtIndex(size, val);
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  }
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  void addAtIndex(int index, int val) {
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    if (index < 0 or index > size) return;
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    if (index == 0) {
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      addAtHead(val);
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      return;
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    }
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    Node *newNode = new Node(val);
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    Node *prev = head;
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    for (int i = 0; i < index - 1; i++) {
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      prev = prev->next;
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    }
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    newNode->next = prev->next;
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    prev->next = newNode;
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    newNode->prev = prev;
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    if (newNode->next) newNode->next->prev = newNode;
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    size++;
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  }
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  void deleteAtIndex(int index) {
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    if (index >= size or index < 0) return;
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    if (index == 0) {
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      Node *temp = head;
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      head = head->next;
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      delete temp;
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      size--;
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      return;
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    }
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    Node *del = head;
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    for (int i = 0; i < index; i++) {
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      del = del->next;
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    }
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    if (del->prev) del->prev->next = del->next;
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    if (del->next) del->next->prev = del->prev;
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    delete del;
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    size--;
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  }
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};