/usr/include/vigra/union_find.hxx is in libvigraimpex-dev 1.9.0+dfsg-10+b2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 | /************************************************************************/
/* */
/* Copyright 2008-2009 by Ullrich Koethe */
/* */
/* This file is part of the VIGRA computer vision library. */
/* The VIGRA Website is */
/* http://hci.iwr.uni-heidelberg.de/vigra/ */
/* Please direct questions, bug reports, and contributions to */
/* ullrich.koethe@iwr.uni-heidelberg.de or */
/* vigra@informatik.uni-hamburg.de */
/* */
/* Permission is hereby granted, free of charge, to any person */
/* obtaining a copy of this software and associated documentation */
/* files (the "Software"), to deal in the Software without */
/* restriction, including without limitation the rights to use, */
/* copy, modify, merge, publish, distribute, sublicense, and/or */
/* sell copies of the Software, and to permit persons to whom the */
/* Software is furnished to do so, subject to the following */
/* conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the */
/* Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES */
/* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND */
/* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT */
/* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, */
/* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
/* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR */
/* OTHER DEALINGS IN THE SOFTWARE. */
/* */
/************************************************************************/
#ifndef VIGRA_UNION_FIND_HXX
#define VIGRA_UNION_FIND_HXX
#include "config.hxx"
#include "error.hxx"
#include "array_vector.hxx"
namespace vigra {
namespace detail {
template <class T>
class UnionFindArray
{
typedef typename ArrayVector<T>::difference_type IndexType;
mutable ArrayVector<T> labels_;
public:
UnionFindArray(T next_free_label = 1)
{
for(T k=0; k <= next_free_label; ++k)
labels_.push_back(k);
}
T nextFreeLabel() const
{
return labels_.back();
}
T find(T label) const
{
T root = label;
while(root != labels_[(IndexType)root])
root = labels_[(IndexType)root];
// path compression
while(label != root)
{
T next = labels_[(IndexType)label];
labels_[(IndexType)label] = root;
label = next;
}
return root;
}
T makeUnion(T l1, T l2)
{
l1 = find(l1);
l2 = find(l2);
if(l1 <= l2)
{
labels_[(IndexType)l2] = l1;
return l1;
}
else
{
labels_[(IndexType)l1] = l2;
return l2;
}
}
T finalizeLabel(T label)
{
if(label == (T)labels_.size()-1)
{
// indeed a new region
vigra_invariant(label < NumericTraits<T>::max(),
"connected components: Need more labels than can be represented in the destination type.");
// create new back entry
labels_.push_back((T)labels_.size());
}
else
{
// no new label => reset the back entry of the label array
labels_.back() = (T)labels_.size()-1;
}
return label;
}
T makeNewLabel()
{
T label = labels_.back();
vigra_invariant(label < NumericTraits<T>::max(),
"connected components: Need more labels than can be represented in the destination type.");
labels_.push_back((T)labels_.size());
return label;
}
unsigned int makeContiguous()
{
// compress trees
unsigned int count = 0;
for(IndexType i=0; i<(IndexType)(labels_.size()-1); ++i)
{
if(labels_[i] == i)
{
labels_[i] = (T)count++;
}
else
{
labels_[i] = labels_[(IndexType)labels_[i]];
}
}
return count-1;
}
T operator[](T label) const
{
return labels_[(IndexType)label];
}
};
} // namespace detail
} // namespace vigra
#endif // VIGRA_UNION_FIND_HXX
|