1 // =========================================================================
2 // @author Leonardo Florez Valencia
3 // @email florez-l@javeriana.edu.co
4 // =========================================================================
6 #ifndef __fpa__Base__MinimumSpanningTree__hxx__
7 #define __fpa__Base__MinimumSpanningTree__hxx__
9 // -------------------------------------------------------------------------
10 template< class _TVertex, class _Superclass >
11 const typename fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
12 TCollisions& fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
13 GetCollisions( ) const
15 return( this->m_Collisions );
18 // -------------------------------------------------------------------------
19 template< class _TVertex, class _Superclass >
20 void fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
21 SetCollisions( const TCollisions& collisions )
23 static const unsigned long _inf =
24 std::numeric_limits< unsigned long >::max( );
25 if( this->m_Collisions == collisions )
28 this->m_Collisions = collisions;
30 // Prepare a front graph
31 unsigned long N = this->m_Collisions.size( );
32 _TMatrix dist( N, _TRow( N, _inf ) );
33 this->m_FrontPaths = dist;
34 for( unsigned long i = 0; i < N; ++i )
36 for( unsigned long j = 0; j < N; ++j )
38 if( this->m_Collisions[ i ][ j ].second )
42 this->m_FrontPaths[ i ][ j ] = j;
43 this->m_FrontPaths[ j ][ i ] = i;
49 this->m_FrontPaths[ i ][ i ] = i;
53 // Use Floyd-Warshall to compute all possible paths between fronts
54 for( unsigned long k = 0; k < N; ++k )
56 for( unsigned long i = 0; i < N; ++i )
58 for( unsigned long j = 0; j < N; ++j )
60 // WARNING: you don't want a numeric overflow!!!
61 unsigned long dik = dist[ i ][ k ];
62 unsigned long dkj = dist[ k ][ j ];
63 unsigned long sum = _inf;
64 if( dik < _inf && dkj < _inf )
67 // Ok, continue Floyd-Warshall
68 if( sum < dist[ i ][ j ] )
71 this->m_FrontPaths[ i ][ j ] = this->m_FrontPaths[ i ][ k ];
83 // -------------------------------------------------------------------------
84 template< class _TVertex, class _Superclass >
85 void fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
88 this->m_Seeds.clear( );
92 // -------------------------------------------------------------------------
93 template< class _TVertex, class _Superclass >
94 void fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
95 AddSeed( const _TVertex& seed )
97 this->m_Seeds.push_back( seed );
101 // -------------------------------------------------------------------------
102 template< class _TVertex, class _Superclass >
103 typename fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
104 TVertices fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
105 GetPath( const _TVertex& a ) const
109 _TVertex p = this->GetParent( it );
112 vertices.push_back( it );
114 p = this->GetParent( it );
117 vertices.push_back( it );
121 // -------------------------------------------------------------------------
122 template< class _TVertex, class _Superclass >
123 typename fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
124 TVertices fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
125 GetPath( const _TVertex& a, const _TVertex& b ) const
127 #error no hace bien el backtracking!
128 static const unsigned long _inf =
129 std::numeric_limits< unsigned long >::max( );
132 TVertices pa = this->GetPath( a );
133 TVertices pb = this->GetPath( b );
134 if( pa.size( ) > 0 && pb.size( ) > 0 )
136 // Find front identifiers
137 unsigned long ia = _inf, ib = _inf;
138 unsigned long N = this->m_Seeds.size( );
139 for( unsigned long i = 0; i < N; ++i )
141 if( this->m_Seeds[ i ] == pa[ pa.size( ) - 1 ] )
143 if( this->m_Seeds[ i ] == pb[ pb.size( ) - 1 ] )
148 // Check if there is a front-jump between given seeds
151 // Compute front path
152 std::vector< long > fpath;
153 fpath.push_back( ia );
156 ia = this->m_FrontPaths[ ia ][ ib ];
157 fpath.push_back( ia );
161 // Continue only if both fronts are connected
162 unsigned int N = fpath.size( );
165 // First path: from start vertex to first collision
166 vertices = this->GetPath(
167 a, this->m_Collisions[ fpath[ 1 ] ][ fpath[ 0 ] ].first
170 // Intermediary paths
171 for( unsigned int i = 1; i < N - 1; ++i )
175 this->m_Collisions[ fpath[ i ] ][ fpath[ i - 1 ] ].first,
176 this->m_Collisions[ fpath[ i ] ][ fpath[ i + 1 ] ].first
178 for( long id = 0; id < ipath.size( ); ++id )
179 vertices.push_back( ipath[ id ] );
183 // Final path: from last collision to end point
186 this->m_Collisions[ fpath[ N - 2 ] ][ fpath[ N - 1 ] ].first, b
188 for( long id = 0; id < lpath.size( ); ++id )
189 vertices.push_back( lpath[ id ] );
195 // Ignore common part: find common ancestor
196 long aIt = pa.size( ) - 1;
197 long bIt = pb.size( ) - 1;
199 while( aIt >= 0 && bIt >= 0 && cont )
201 cont = ( pa[ aIt ] == pb[ bIt ] );
210 for( long cIt = 0; cIt <= aIt; ++cIt )
211 vertices.push_back( pa[ cIt ] );
212 for( ; bIt >= 0; --bIt )
213 vertices.push_back( pb[ bIt ] );
221 // -------------------------------------------------------------------------
222 template< class _TVertex, class _Superclass >
223 fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
224 MinimumSpanningTree( )
229 // -------------------------------------------------------------------------
230 template< class _TVertex, class _Superclass >
231 fpa::Base::MinimumSpanningTree< _TVertex, _Superclass >::
232 ~MinimumSpanningTree( )
236 #endif // __fpa__Base__MinimumSpanningTree__hxx__