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  1. #include <cstdio>
  2.  
  3. template<typename T>class List
  4. {
  5. public:
  6.     class Item;
  7. private:
  8.     class Next
  9.     {
  10.         Item *next;
  11.         friend class List;
  12.     };
  13.     class Prev
  14.     {
  15.         Item *prev;
  16.         friend class List;
  17.     };
  18.     Next zero;
  19.     Prev stop;
  20. public:
  21.     class Item : public Next, public Prev
  22.     {
  23.         friend class List;
  24.     public:
  25.         T data;
  26.         Item(T data) : data(data) {}
  27.     };
  28.     List()
  29.     {
  30.         zero.next = static_cast<Item*>(&stop);
  31.         stop.prev = static_cast<Item*>(&zero);
  32.     }
  33.     Item* push(T data, List::Item *before = nullptr)
  34.     {
  35.         if (!before) before = static_cast<Item*>(&zero);
  36.         Item *self = new Item(data);
  37.         before->prev->next = self;
  38.         self->prev = before->prev;
  39.         before->prev = self;
  40.         self->next = before;
  41.         return self;
  42.     }
  43.     void enumerate(void(func)(T data))
  44.     {
  45.         for (auto it = zero.next; it != static_cast<Item*>(&stop); it = it->next)
  46.             func(it->data);
  47.     }
  48. };
  49.  
  50. int main()
  51. {
  52.     List<const char*> man;
  53.     man.push("кресты");
  54.     auto p1 = man.push("лучший");
  55.     auto p2 = man.push("в мире");
  56.     man.enumerate([](const char *s) {
  57.         puts(s);
  58.     });
  59.     puts("");
  60.     man.push("язык", p2);
  61.     man.push("самый", p1);
  62.     man.enumerate([](const char *s) {
  63.         puts(s);
  64.     });
  65.     return 0;
  66. }
  67.  
Success #stdin #stdout 0s 4284KB
comments (?)
stdin 
Standard input is empty
stdout 
кресты
лучший
в мире

кресты
самый
лучший
язык
в мире
https://ideone.com/bOTA27
language:
C++ (gcc 8.3)
created:
5 years ago
visibility:
public

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