source: trunk/libs/newlib/src/include/partition.h @ 478

Last change on this file since 478 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 2.8 KB
Line 
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
40extern "C" {
41#endif /* __cplusplus */
42
43#include "ansidecl.h"
44#include <stdio.h>
45
46struct partition_elem
47{
48  /* The next element in this class.  Elements in each class form a
49     circular list.  */
50  struct partition_elem* next;
51  /* The canonical element that represents the class containing this
52     element.  */
53  int class_element;
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
59typedef 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
67extern partition partition_new (int);
68extern void partition_delete (partition);
69extern int partition_union (partition, int, int);
70extern 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 */
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