|
0
|
1 /* List implementation of a partition of consecutive integers.
|
|
|
2 Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
|
|
|
3 Contributed by CodeSourcery, LLC.
|
|
|
4
|
|
|
5 This file is part of GCC.
|
|
|
6
|
|
|
7 GCC is free software; you can redistribute it and/or modify
|
|
|
8 it under the terms of the GNU General Public License as published by
|
|
|
9 the Free Software Foundation; either version 2, or (at your option)
|
|
|
10 any later version.
|
|
|
11
|
|
|
12 GCC is distributed in the hope that it will be useful,
|
|
|
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
15 GNU General Public License for more details.
|
|
|
16
|
|
|
17 You should have received a copy of the GNU General Public License
|
|
|
18 along with GCC; see the file COPYING. If not, write to
|
|
|
19 the Free Software Foundation, 51 Franklin Street - Fifth Floor,
|
|
|
20 Boston, MA 02110-1301, USA. */
|
|
|
21
|
|
|
22 /* This package implements a partition of consecutive integers. The
|
|
|
23 elements are partitioned into classes. Each class is represented
|
|
|
24 by one of its elements, the canonical element, which is chosen
|
|
|
25 arbitrarily from elements in the class. The principal operations
|
|
|
26 on a partition are FIND, which takes an element, determines its
|
|
|
27 class, and returns the canonical element for that class, and UNION,
|
|
|
28 which unites the two classes that contain two given elements into a
|
|
|
29 single class.
|
|
|
30
|
|
|
31 The list implementation used here provides constant-time finds. By
|
|
|
32 storing the size of each class with the class's canonical element,
|
|
|
33 it is able to perform unions over all the classes in the partition
|
|
|
34 in O (N log N) time. */
|
|
|
35
|
|
|
36 #ifndef _PARTITION_H
|
|
|
37 #define _PARTITION_H
|
|
|
38
|
|
|
39 #ifdef __cplusplus
|
|
|
40 extern "C" {
|
|
|
41 #endif /* __cplusplus */
|
|
|
42
|
|
|
43 #include "ansidecl.h"
|
|
|
44 #include <stdio.h>
|
|
|
45
|
|
|
46 struct partition_elem
|
|
|
47 {
|
|
|
48 /* The canonical element that represents the class containing this
|
|
|
49 element. */
|
|
|
50 int class_element;
|
|
|
51 /* The next element in this class. Elements in each class form a
|
|
|
52 circular list. */
|
|
|
53 struct partition_elem* next;
|
|
|
54 /* The number of elements in this class. Valid only if this is the
|
|
|
55 canonical element for its class. */
|
|
|
56 unsigned class_count;
|
|
|
57 };
|
|
|
58
|
|
|
59 typedef struct partition_def
|
|
|
60 {
|
|
|
61 /* The number of elements in this partition. */
|
|
|
62 int num_elements;
|
|
|
63 /* The elements in the partition. */
|
|
|
64 struct partition_elem elements[1];
|
|
|
65 } *partition;
|
|
|
66
|
|
|
67 extern partition partition_new (int);
|
|
|
68 extern void partition_delete (partition);
|
|
|
69 extern int partition_union (partition, int, int);
|
|
|
70 extern void partition_print (partition, FILE*);
|
|
|
71
|
|
|
72 /* Returns the canonical element corresponding to the class containing
|
|
|
73 ELEMENT__ in PARTITION__. */
|
|
|
74
|
|
|
75 #define partition_find(partition__, element__) \
|
|
|
76 ((partition__)->elements[(element__)].class_element)
|
|
|
77
|
|
|
78 #ifdef __cplusplus
|
|
|
79 }
|
|
|
80 #endif /* __cplusplus */
|
|
|
81
|
|
|
82 #endif /* _PARTITION_H */
|
