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
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
#include "booksim.hpp"
#include <iostream>
#include "maxsize.hpp"
// shortest augmenting path:
//
// for all unmatched left nodes,
// push node onto work stack
// end
//
// for all j,
// from[j] = undefined
// end
//
// do,
//
// while( !stack.empty ),
//
// nl = stack.pop
// for each edge (nl,j),
// if ( ( lmatch[nl] != j ) && ( from[j] == undefined ) ),
// if ( rmatch[j] == undefined ),
// stop // augmenting path found
// else
// from[j] = nl
// newstack.push( rmatch[j] )
// end
// end
// end
// end
//
// stack = newstack
// end
//
//#define DEBUG_MAXSIZE
//#define PRINT_MATCHING
MaxSizeMatch::MaxSizeMatch( const Configuration &config,
Module *parent, const string& name,
int inputs, int outputs ) :
DenseAllocator( config, parent, name, inputs, outputs )
{
_from = new int [_outputs];
_s = new int [_inputs];
_ns = new int [_inputs];
}
MaxSizeMatch::~MaxSizeMatch( )
{
delete [] _from;
delete [] _s;
delete [] _ns;
}
void MaxSizeMatch::Allocate( )
{
// clear matching
for ( int i = 0; i < _inputs; ++i ) {
_inmatch[i] = -1;
}
for ( int j = 0; j < _outputs; ++j ) {
_outmatch[j] = -1;
}
// augment as many times as possible
// (this is an O(N^3) maximum-size matching algorithm)
while ( _ShortestAugmenting( ) );
}
bool MaxSizeMatch::_ShortestAugmenting( )
{
int i, j, jn;
int slen, nslen;
int *t;
slen = 0;
for ( i = 0; i < _inputs; ++i ) {
if ( _inmatch[i] == -1 ) { // start with unmatched left nodes
_s[slen] = i;
slen++;
}
_from[i] = -1;
}
for ( int iter = 0; iter < _inputs; iter++ ) {
nslen = 0;
for ( int e = 0; e < slen; ++e ) {
i = _s[e];
for ( j = 0; j < _outputs; ++j ) {
if ( ( _request[i][j].label != -1 ) && // edge (i,j) exists
( _inmatch[i] != j ) && // (i,j) is not contained in the current matching
( _from[j] == -1 ) ) { // no shorter path to j exists
_from[j] = i; // how did we get to j?
#ifdef DEBUG_MAXSIZE
cout << " got to " << j << " from " << i << endl;
#endif
if ( _outmatch[j] == -1 ) { // j is unmatched -- augmenting path found
goto found_augmenting;
} else { // j is matched
_ns[nslen] = _outmatch[j]; // add the destination of this edge to the leaf nodes
nslen++;
#ifdef DEBUG_MAXSIZE
cout << " adding " << _outmatch[j] << endl;
#endif
}
}
}
}
// no augmenting path found yet, swap stacks
t = _s;
_s = _ns;
_ns = t;
slen = nslen;
}
return false; // no augmenting paths
found_augmenting:
// the augmenting path ends at node j on the right
#ifdef DEBUG_MAXSIZE
cout << "Found path: " << j << "c <- ";
#endif
i = _from[j];
_outmatch[j] = i;
#ifdef DEBUG_MAXSIZE
cout << i;
#endif
while ( _inmatch[i] != -1 ) { // loop until the end of the path
jn = _inmatch[i]; // remove previous edge (i,jn) and add (i,j)
_inmatch[i] = j;
#ifdef DEBUG_MAXSIZE
cout << " <- " << j << "c <- ";
#endif
j = jn; // add edge from (jn,in)
i = _from[j];
_outmatch[j] = i;
#ifdef DEBUG_MAXSIZE
cout << i;
#endif
}
#ifdef DEBUG_MAXSIZE
cout << endl;
#endif
_inmatch[i] = j;
#ifdef PRINT_MATCHING
cout << "left matching: ";
for ( i = 0; i < _inputs; i++ ) {
cout << _inmatch[i] << " ";
}
cout << endl;
cout << "right matching: ";
for ( i = 0; i < _outputs; i++ ) {
cout << _outmatch[i] << " ";
}
cout << endl;
#endif
return true;
}
|
