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Is there something like Haskell Data.Sequence in C ++?

Does the library use C++something like a container Haskell Data.Sequence?

I'm most interested in:

  • Preservation of the order of elements (in which they were inserted).
  • O(logn)index access. Aka operator[](size_type pos).
  • O(logn) insert / delete in the middle (by index).
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1 answer

It seems to me that to implement such a data structure you will need a tree that stores the number of elements in each node. It allows you to insert and retrieve in O (log (N)), and indexes are supported simply by counting the number of elements in the “left” given node in the tree.

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A node :

template<typename T>
struct Node {
  Node* left;
  Node* right;
  size_t elements;
  T value

  T& access(size_t index) {
    if (left->elements == index) {
      return value;
    } else if (left->elements > index) {
      return left->access(index);
    } else {
      return right->access(index - left->elements - 1);
    }
  }

  void insert(size_t index, T&& value) {
    // insert `value` at right place, increment `elements`
  }
}

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