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/* List implementation of a partition of consecutive integers. |
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Copyright (C) 2000-2021 Free Software Foundation, Inc. |
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Contributed by CodeSourcery, LLC. |
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|
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This file is part of GCC. |
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|
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GCC is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2, or (at your option) |
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any later version. |
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|
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GCC is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with GCC; see the file COPYING. If not, write to |
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the Free Software Foundation, 51 Franklin Street - Fifth Floor, |
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Boston, MA 02110-1301, USA. */ |
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|
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/* This package implements a partition of consecutive integers. The |
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elements are partitioned into classes. Each class is represented |
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by one of its elements, the canonical element, which is chosen |
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arbitrarily from elements in the class. The principal operations |
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on a partition are FIND, which takes an element, determines its |
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class, and returns the canonical element for that class, and UNION, |
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which unites the two classes that contain two given elements into a |
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single class. |
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|
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The list implementation used here provides constant-time finds. By |
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storing the size of each class with the class's canonical element, |
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it is able to perform unions over all the classes in the partition |
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in O (N log N) time. */ |
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|
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#ifndef _PARTITION_H |
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#define _PARTITION_H |
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|
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#ifdef __cplusplus |
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extern "C" { |
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#endif /* __cplusplus */ |
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|
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#include "ansidecl.h" |
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#include <stdio.h> |
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|
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struct partition_elem |
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{ |
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/* The next element in this class. Elements in each class form a |
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circular list. */ |
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struct partition_elem* next; |
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/* The canonical element that represents the class containing this |
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element. */ |
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int class_element; |
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/* The number of elements in this class. Valid only if this is the |
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canonical element for its class. */ |
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unsigned class_count; |
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}; |
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|
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typedef struct partition_def |
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{ |
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/* The number of elements in this partition. */ |
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int num_elements; |
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/* The elements in the partition. */ |
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struct partition_elem elements[1]; |
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} *partition; |
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|
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extern partition partition_new (int); |
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extern void partition_delete (partition); |
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extern int partition_union (partition, int, int); |
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extern void partition_print (partition, FILE*); |
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|
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/* Returns the canonical element corresponding to the class containing |
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ELEMENT__ in PARTITION__. */ |
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|
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#define partition_find(partition__, element__) \ |
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((partition__)->elements[(element__)].class_element) |
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|
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#ifdef __cplusplus |
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} |
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#endif /* __cplusplus */ |
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|
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#endif /* _PARTITION_H */ |
