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Diffstat (limited to 'contrib/gcclibs/include/partition.h')
-rw-r--r-- | contrib/gcclibs/include/partition.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/contrib/gcclibs/include/partition.h b/contrib/gcclibs/include/partition.h new file mode 100644 index 0000000..d8b554f --- /dev/null +++ b/contrib/gcclibs/include/partition.h @@ -0,0 +1,82 @@ +/* List implementation of a partition of consecutive integers. + Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc. + Contributed by CodeSourcery, LLC. + + This file is part of GCC. + + GCC is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + GCC is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING. If not, write to + the Free Software Foundation, 51 Franklin Street - Fifth Floor, + Boston, MA 02110-1301, USA. */ + +/* This package implements a partition of consecutive integers. The + elements are partitioned into classes. Each class is represented + by one of its elements, the canonical element, which is chosen + arbitrarily from elements in the class. The principal operations + on a partition are FIND, which takes an element, determines its + class, and returns the canonical element for that class, and UNION, + which unites the two classes that contain two given elements into a + single class. + + The list implementation used here provides constant-time finds. By + storing the size of each class with the class's canonical element, + it is able to perform unions over all the classes in the partition + in O (N log N) time. */ + +#ifndef _PARTITION_H +#define _PARTITION_H + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +#include "ansidecl.h" +#include <stdio.h> + +struct partition_elem +{ + /* The canonical element that represents the class containing this + element. */ + int class_element; + /* The next element in this class. Elements in each class form a + circular list. */ + struct partition_elem* next; + /* The number of elements in this class. Valid only if this is the + canonical element for its class. */ + unsigned class_count; +}; + +typedef struct partition_def +{ + /* The number of elements in this partition. */ + int num_elements; + /* The elements in the partition. */ + struct partition_elem elements[1]; +} *partition; + +extern partition partition_new (int); +extern void partition_delete (partition); +extern int partition_union (partition, int, int); +extern void partition_print (partition, FILE*); + +/* Returns the canonical element corresponding to the class containing + ELEMENT__ in PARTITION__. */ + +#define partition_find(partition__, element__) \ + ((partition__)->elements[(element__)].class_element) + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _PARTITION_H */ |