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diff --git a/src/Coxeter_triangulation/include/gudhi/Permutahedral_representation/Set_partition_iterator.h b/src/Coxeter_triangulation/include/gudhi/Permutahedral_representation/Set_partition_iterator.h
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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_SET_PARTITION_ITERATOR_H_
+#define PERMUTAHEDRAL_REPRESENTATION_SET_PARTITION_ITERATOR_H_
+
+#include <vector>
+#include <limits>
+#include <boost/range/iterator_range.hpp>
+
+namespace Gudhi {
+
+namespace coxeter_triangulation {
+
+typedef unsigned uint;
+
+/** \brief Class that allows the user to generate set partitions of a set {0,...,n-1} in k parts.
+ *
+ */
+class Set_partition_iterator
+ : public boost::iterator_facade<Set_partition_iterator, std::vector<std::vector<uint>> const,
+ boost::forward_traversal_tag> {
+ using value_t = std::vector<std::vector<uint>>;
+
+ private:
+ friend class boost::iterator_core_access;
+
+ bool equal(Set_partition_iterator const& other) const { return (is_end_ && other.is_end_); }
+
+ value_t const& dereference() const { return value_; }
+
+ void update_value() {
+ for (uint i = 0; i < k_; i++) value_[i].clear();
+ for (uint i = 0; i < n_; i++) value_[rgs_[i]].push_back(i);
+ }
+
+ void increment() {
+ if (k_ <= 1) {
+ is_end_ = true;
+ return;
+ }
+ uint i = n_ - 1;
+ while (rgs_[i] + 1 > max_[i] || rgs_[i] + 1 >= k_) i--;
+ if (i == 0) {
+ is_end_ = true;
+ return;
+ }
+ rgs_[i]++;
+ uint mm = max_[i];
+ mm += (rgs_[i] >= mm);
+ max_[i + 1] = mm;
+ while (++i < n_) {
+ rgs_[i] = 0;
+ max_[i + 1] = mm;
+ }
+ uint p = k_;
+ if (mm < p) do {
+ max_[i] = p;
+ --i;
+ --p;
+ rgs_[i] = p;
+ } while (max_[i] < p);
+ update_value();
+ }
+
+ public:
+ Set_partition_iterator(const uint& n, const uint& k)
+ : value_(k), rgs_(n, 0), max_(n + 1), is_end_(n == 0), n_(n), k_(k) {
+ max_[0] = std::numeric_limits<uint>::max();
+ for (uint i = 0; i <= n - k; ++i) value_[0].push_back(i);
+ for (uint i = n - k + 1, j = 1; i < n; ++i, ++j) {
+ rgs_[i] = j;
+ value_[j].push_back(i);
+ }
+ for (uint i = 1; i <= n; i++) max_[i] = rgs_[i - 1] + 1;
+ update_value();
+ }
+
+ // Used for creating an end iterator
+ Set_partition_iterator() : is_end_(true), n_(0), k_(0) {}
+
+ void reinitialize() {
+ if (n_ > 0) is_end_ = false;
+ for (uint i = 0; i <= n_ - k_; ++i) rgs_[i] = 0;
+ for (uint i = n_ - k_ + 1, j = 1; i < n_; ++i, ++j) rgs_[i] = j;
+ for (uint i = 1; i <= n_; i++) max_[i] = rgs_[i - 1] + 1;
+ update_value();
+ }
+
+ private:
+ value_t value_; // the dereference value
+ std::vector<uint> rgs_; // restricted growth string
+ std::vector<uint> max_; // max_[i] = max(rgs_[0],...,rgs[i-1]) + 1
+ bool is_end_; // is true when the current permutation is the final one
+
+ uint n_;
+ uint k_;
+};
+
+} // namespace coxeter_triangulation
+
+} // namespace Gudhi
+
+#endif