Design Browser History LeetCode solution in C++

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class Node {
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 public:
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  string url;
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  Node *next;
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  Node *back;
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  Node(string s) {
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    url = s;
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    next = NULL;
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    back = NULL;
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  }
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};
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class BrowserHistory {
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  Node *head;
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 public:
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  BrowserHistory(string homepage) {
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    head = new Node(homepage);
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  }
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  void visit(string url) {
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    Node *ptr = new Node(url);
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    head->next = ptr;
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    ptr->back = head;
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    head = ptr;
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  }
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  string back(int steps) {
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    while (head->back && steps--) {
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      head = head->back;
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    }
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    return head->url;
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  }
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  string forward(int steps) {
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    while (head->next && steps--) {
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      head = head->next;
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    }
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    return head->url;
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  }
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};