1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
/* $Id: stack.c,v 1.1.1.1 2004/12/23 04:04:31 ellson Exp $ $Revision: 1.1.1.1 $ */
/* vim:set shiftwidth=4 ts=8: */
/**********************************************************
* This software is part of the graphviz package *
* http://www.graphviz.org/ *
* *
* Copyright (c) 1994-2004 AT&T Corp. *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Corp. *
* *
* Information and Software Systems Research *
* AT&T Research, Florham Park NJ *
**********************************************************/
#include "stack.h"
#include "circular.h"
#include <assert.h>
nstack_t *mkStack()
{
nstack_t *s;
s = NEW(nstack_t);
s->top = NULL;
s->sz = 0;
return s;
}
void freeStack(nstack_t * s)
{
free(s);
}
void stackPush(nstack_t * s, Agnode_t * n)
{
SET_ONSTACK(n);
NEXT(n) = s->top;
s->top = n;
s->sz += 1;
}
Agnode_t *stackPop(nstack_t * s)
{
Agnode_t *top = s->top;
if (top) {
assert(s->sz > 0);
UNSET_ONSTACK(top);
s->top = NEXT(top);
s->sz -= 1;
} else {
assert(0);
}
return top;
}
int stackSize(nstack_t * s)
{
return s->sz;
}
/* stackCheck:
* Return true if n in on the stack.
*/
int stackCheck(nstack_t * s, Agnode_t * n)
{
return ONSTACK(n);
#ifdef OLD
stackitem_t *top = s->top;
Agnode_t *node;
while (top != NULL) {
node = top->data;
if (node == n)
return 1;
top = top->next;
}
return 0;
#endif
}
#ifdef DEBUG
void printStack(nstack_t * s)
{
Agnode_t *n;
for (n = s->top; n; n = NEXT(n))
fprintf(stderr, " %s", n->name);
fprintf(stderr, "\n");
}
#endif
|
