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+/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ * See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ * Author(s): Siargey Kachanovich
+ *
+ * Copyright (C) 2019 Inria
+ *
+ * Modification(s):
+ * - YYYY/MM Author: Description of the modification
+ */
+
+#ifndef PERMUTAHEDRAL_REPRESENTATION_ORDERED_SET_PARTITION_ITERATOR_H_
+#define PERMUTAHEDRAL_REPRESENTATION_ORDERED_SET_PARTITION_ITERATOR_H_
+
+#include <vector>
+#include <limits>
+
+#include <gudhi/Permutahedral_representation/Permutation_iterator.h>
+#include <gudhi/Permutahedral_representation/Set_partition_iterator.h>
+
+#include <boost/range/iterator_range.hpp>
+
+namespace Gudhi {
+
+namespace coxeter_triangulation {
+
+typedef unsigned uint;
+
+/** \brief Class that represents an ordered set partition of a set {0,...,n-1} in k parts as
+ * a pair of an unordered set partition given in lexicographic order and
+ * a permutation of the parts.
+ */
+struct Ordered_set_partition {
+ Set_partition_iterator s_it_;
+ Permutation_iterator p_it_;
+
+ // Ordered_set_partition(const Set_partition_iterator& s_it, const Permutation_iterator& p_it)
+ // : s_it_(s_it), p_it_(p_it) {}
+
+ const std::vector<uint> operator[](const uint& i) const { return (*s_it_)[(*p_it_)[i]]; }
+
+ std::size_t size() const { return s_it_->size(); }
+};
+
+/** \brief Class that allows the user to generate set partitions of a set {0,...,n-1} in k parts.
+ *
+ */
+class Ordered_set_partition_iterator
+ : public boost::iterator_facade<Ordered_set_partition_iterator, Ordered_set_partition const,
+ boost::forward_traversal_tag> {
+ using value_t = Ordered_set_partition;
+
+ private:
+ friend class boost::iterator_core_access;
+
+ bool equal(Ordered_set_partition_iterator const& other) const { return (is_end_ && other.is_end_); }
+
+ value_t const& dereference() const { return value_; }
+
+ void increment() {
+ if (++value_.p_it_ == p_end_) {
+ if (++value_.s_it_ == s_end_) {
+ is_end_ = true;
+ return;
+ } else
+ value_.p_it_.reinitialize();
+ }
+ }
+
+ public:
+ Ordered_set_partition_iterator(const uint& n, const uint& k)
+ : value_({Set_partition_iterator(n, k), Permutation_iterator(k)}), is_end_(n == 0) {}
+
+ // Used for the creating an end iterator
+ Ordered_set_partition_iterator() : is_end_(true) {}
+
+ void reinitialize() {
+ is_end_ = false;
+ value_.p_it_.reinitialize();
+ value_.s_it_.reinitialize();
+ }
+
+ private:
+ Set_partition_iterator s_end_; // Set partition iterator and the corresponding end iterator
+ Permutation_iterator p_end_; // Permutation iterator and the corresponding end iterator
+ value_t value_; // the dereference value
+ bool is_end_; // is true when the current permutation is the final one
+};
+
+} // namespace coxeter_triangulation
+
+} // namespace Gudhi
+
+#endif