1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the class library */
4 /* SoPlex --- the Sequential object-oriented simPlex. */
5 /* */
6 /* Copyright (C) 1996-2021 Konrad-Zuse-Zentrum */
7 /* fuer Informationstechnik Berlin */
8 /* */
9 /* SoPlex is distributed under the terms of the ZIB Academic Licence. */
10 /* */
11 /* You should have received a copy of the ZIB Academic License */
12 /* along with SoPlex; see the file COPYING. If not email to soplex@zib.de. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15
16 /**@file spxid.h
17 * @brief Row and columns Id's \ref soplex::SPxLP "SPxLP".
18 */
19 #ifndef _SPXID_H_
20 #define _SPXID_H_
21
22 #include <iostream>
23
24 #include "soplex/datakey.h"
25
26 namespace soplex
27 {
28 class SPxId;
29
30 /**@brief Ids for LP columns.
31 * @ingroup Algo
32 *
33 * Class SPxColId provides #DataKey%s for the
34 * column indices of an SPxLP.
35 */
36 class SPxColId : public DataKey
37 {
38 public:
39 /// default constructor.
40 SPxColId()
41 {}
42 /// copy constructor from DataKey.
43 explicit SPxColId(const DataKey& p_key);
44 /// copy constructor from SPxId.
45 explicit SPxColId(const SPxId& p_key);
46 };
47
48
49 /**@brief Ids for LP rows.
50 * @ingroup Algo
51 *
52 * Class SPxRowId provides #DataKey%s for the row
53 * indices of an SPxLP.
54 */
55 class SPxRowId : public DataKey
56 {
57 public:
58 /// default constructor.
59 SPxRowId()
60 {}
61 /// copy constructor from DataKey.
62 explicit SPxRowId(const DataKey& p_key);
63 /// copy constructor from SPxId.
64 explicit SPxRowId(const SPxId& p_key);
65 };
66
67 /**@brief Generic Ids for LP rows or columns.
68 * @ingroup Algo
69 *
70 * Both \ref soplex::SPxColId "SPxColIds" and \ref soplex::SPxRowId
71 * "SPxRowIds" may be treated uniformly as #SPxId%s:
72 *
73 * Rows and columns are numbered from 0 to num()-1 and 0 to dim()-1
74 * respectively. These numbers may be used to select individual rows or
75 * columns. However, these numbers may change if other rows or columns are
76 * added or removed.
77 *
78 * Further, each row or column of the problem matrix is assigned a \ref
79 * soplex::SPxRowId "SPxRowId" or \ref soplex::SPxColId "SPxColId",
80 * respectively. They are be used to select individual rows or columns just
81 * like numbers. In contrast to row and column numbers, ids remain unchanged
82 * for the time a row or column belongs to a SPxLP, no matter what other
83 * rows or columns are added to it or removed from it.
84 */
85 class SPxId : public DataKey
86 {
87 friend std::ostream& operator<<(std::ostream& os, const SPxId& id);
88
89 public:
90
91 //--------------------------------
92 /**@name Types */
93 ///@{
94 /// type of the id.
95 enum Type
96 {
97 ROW_ID = -1, ///< row identifier.
98 INVALID = 0, ///< invalid id.
99 COL_ID = 1 ///< column identifier.
100 };
101 ///@}
102
103 //------------------------------------
104 /**@name Construction / destruction */
105 ///@{
106 /// default constructor. Constructs an invalid id.
107 SPxId()
108 : DataKey(INVALID, -1)
109 {}
110 /// constructs an id out of a column identifier \p cid.
111 explicit SPxId(const SPxColId& cid)
112 : DataKey(COL_ID, cid.idx)
113 {}
114 /// constructs an id out of a row identifier \p rid.
115 explicit SPxId(const SPxRowId& rid)
116 : DataKey(ROW_ID, rid.idx)
117 {}
118
119 /// assignment operator
120 SPxId& operator=(const SPxColId& cid)
121 {
122 DataKey::operator= (cid);
123 info = COL_ID;
124 return *this;
125 }
126 /// assignment operator
127 SPxId& operator=(const SPxRowId& rid)
128 {
129 DataKey::operator= (rid);
130 info = ROW_ID;
131 return *this;
132 }
133 ///@}
134
135 //--------------------------------
136 /**@name Access / modification */
137 ///@{
138 /// returns the type of the id.
139 inline Type type() const
140 {
141 return info ? (info < 0 ? ROW_ID : COL_ID) : INVALID;
142 }
143 /// returns TRUE iff the id is a valid column or row identifier.
144 inline bool isValid() const
145 {
146 return info != 0;
147 }
148 /// makes the id invalid.
149 inline void inValidate()
150 {
151 info = 0;
152 }
153 /// is id a row id?
154 inline bool isSPxRowId() const
155 {
156 return info < 0;
157 }
158 /// is id a column id?
159 inline bool isSPxColId() const
160 {
161 return info > 0;
162 }
163 ///@}
164
165 //------------------------------------
166 /**@name Comparison of Ids */
167 ///@{
168 /// equality operator.
169 int operator==(const SPxId& id) const
170 {
171 return (this == &id);
172 }
173 /// inequality operator.
174 int operator!=(const SPxId& id) const
175 {
176 return (this != &id);
177 }
178 /// less then operator
179 bool operator<(const SPxId& id) const
180 {
181 return getIdx() < id.getIdx();
182 }
183 ///@}
184 };
185
186
187 } // namespace soplex
188 #endif // _SPXID_H_
189