1/* A Fibonacci heap datatype.
2   Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2009
3   Free Software Foundation, Inc.
4   Contributed by Daniel Berlin (dan@cgsoftware.com).
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it
9under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 2, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING.  If not, write to
20the Free Software Foundation, 51 Franklin Street - Fifth Floor,
21Boston, MA 02110-1301, USA.  */
22
23/* Fibonacci heaps are somewhat complex, but, there's an article in
24   DDJ that explains them pretty well:
25
26   http://www.ddj.com/articles/1997/9701/9701o/9701o.htm?topic=algoritms
27
28   Introduction to algorithms by Corman and Rivest also goes over them.
29
30   The original paper that introduced them is "Fibonacci heaps and their
31   uses in improved network optimization algorithms" by Tarjan and
32   Fredman (JACM 34(3), July 1987).
33
34   Amortized and real worst case time for operations:
35
36   ExtractMin: O(lg n) amortized. O(n) worst case.
37   DecreaseKey: O(1) amortized.  O(lg n) worst case.
38   Insert: O(2) amortized. O(1) actual.
39   Union: O(1) amortized. O(1) actual.  */
40
41#ifndef _FIBHEAP_H_
42#define _FIBHEAP_H_
43
44#include "ansidecl.h"
45
46#ifdef __cplusplus
47extern "C" {
48#endif
49
50typedef long fibheapkey_t;
51
52typedef struct fibheap
53{
54  size_t nodes;
55  struct fibnode *min;
56  struct fibnode *root;
57} *fibheap_t;
58
59typedef struct fibnode
60{
61  struct fibnode *parent;
62  struct fibnode *child;
63  struct fibnode *left;
64  struct fibnode *right;
65  fibheapkey_t key;
66  void *data;
67#if defined (__GNUC__) && (!defined (SIZEOF_INT) || SIZEOF_INT < 4)
68  __extension__ unsigned long int degree : 31;
69  __extension__ unsigned long int mark : 1;
70#else
71  unsigned int degree : 31;
72  unsigned int mark : 1;
73#endif
74} *fibnode_t;
75
76extern fibheap_t fibheap_new (void);
77extern fibnode_t fibheap_insert (fibheap_t, fibheapkey_t, void *);
78extern int fibheap_empty (fibheap_t);
79extern fibheapkey_t fibheap_min_key (fibheap_t);
80extern fibheapkey_t fibheap_replace_key (fibheap_t, fibnode_t,
81                                         fibheapkey_t);
82extern void *fibheap_replace_key_data (fibheap_t, fibnode_t,
83                                       fibheapkey_t, void *);
84extern void *fibheap_extract_min (fibheap_t);
85extern void *fibheap_min (fibheap_t);
86extern void *fibheap_replace_data (fibheap_t, fibnode_t, void *);
87extern void *fibheap_delete_node (fibheap_t, fibnode_t);
88extern void fibheap_delete (fibheap_t);
89extern fibheap_t fibheap_union (fibheap_t, fibheap_t);
90
91#ifdef __cplusplus
92}
93#endif
94
95#endif /* _FIBHEAP_H_ */
96