| 42 | } |
| 43 | |
| 44 | void Graph::merge( VertId remnant, VertId dead, std::function<void(EdgeId, EdgeId)> onMergeEdges ) |
| 45 | { |
| 46 | assert( remnant.valid() && validVerts_.test( remnant ) ); |
| 47 | assert( dead.valid() && validVerts_.test( dead ) ); |
| 48 | assert( remnant != dead ); |
| 49 | validVerts_.reset( dead ); |
| 50 | |
| 51 | struct NeiEdge |
| 52 | { |
| 53 | VertId nei; |
| 54 | EdgeId e; |
| 55 | auto operator<=>(const NeiEdge&) const = default; |
| 56 | }; |
| 57 | std::vector<NeiEdge> neiEdges; |
| 58 | neiEdges.reserve( neighboursPerVertex_[remnant].size() + neighboursPerVertex_[dead].size() ); |
| 59 | for ( auto e : neighboursPerVertex_[remnant] ) |
| 60 | { |
| 61 | const auto ends = endsPerEdge_[e]; |
| 62 | const auto nei = ends.otherEnd( remnant ); |
| 63 | if ( nei == dead ) |
| 64 | { |
| 65 | validEdges_.reset( e ); |
| 66 | continue; |
| 67 | } |
| 68 | neiEdges.push_back( { nei, e } ); |
| 69 | } |
| 70 | for ( auto e : neighboursPerVertex_[dead] ) |
| 71 | { |
| 72 | auto & ends = endsPerEdge_[e]; |
| 73 | const auto nei = ends.otherEnd( dead ); |
| 74 | if ( nei == remnant ) |
| 75 | { |
| 76 | validEdges_.reset( e ); |
| 77 | continue; |
| 78 | } |
| 79 | ends.replaceEnd( dead, remnant ); |
| 80 | neiEdges.push_back( { nei, e } ); |
| 81 | } |
| 82 | std::sort( neiEdges.begin(), neiEdges.end() ); |
| 83 | |
| 84 | // reuse the memory for neighbors |
| 85 | Neighbours neis; |
| 86 | if ( neighboursPerVertex_[remnant].size() >= neighboursPerVertex_[dead].size() ) |
| 87 | neis = std::move( neighboursPerVertex_[remnant] ); |
| 88 | else |
| 89 | neis = std::move( neighboursPerVertex_[dead] ); |
| 90 | neis.clear(); |
| 91 | neighboursPerVertex_[dead] = {}; |
| 92 | |
| 93 | for ( const auto & x : neiEdges ) |
| 94 | { |
| 95 | if ( neis.empty() || endsPerEdge_[neis.back()].otherEnd( remnant ) != x.nei ) |
| 96 | { |
| 97 | assert( validEdges_.test( x.e ) ); |
| 98 | neis.push_back( x.e ); |
| 99 | continue; |
| 100 | } |
| 101 | validEdges_.reset( x.e ); |