[1636] | 1 | /* -*- C++ -*- |
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| 2 | * demo/coloring.cc - Part of LEMON, a generic C++ optimization library |
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| 3 | * |
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| 4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 5 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 6 | * |
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| 7 | * Permission to use, modify and distribute this software is granted |
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| 8 | * provided that this copyright notice appears in all copies. For |
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| 9 | * precise terms see the accompanying LICENSE file. |
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| 10 | * |
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| 11 | * This software is provided "AS IS" with no warranty of any kind, |
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| 12 | * express or implied, and with no claim as to its suitability for any |
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| 13 | * purpose. |
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| 14 | * |
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| 15 | */ |
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| 16 | |
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[1422] | 17 | #include <vector> |
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| 18 | |
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| 19 | #include <lemon/smart_graph.h> |
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| 20 | #include <lemon/bin_heap.h> |
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| 21 | #include <lemon/graph_reader.h> |
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| 22 | #include <lemon/graph_to_eps.h> |
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| 23 | |
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[1560] | 24 | #include <fstream> |
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| 25 | #include <iostream> |
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| 26 | |
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| 27 | |
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[1422] | 28 | using namespace std; |
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| 29 | using namespace lemon; |
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| 30 | |
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[1683] | 31 | int main() { |
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[1560] | 32 | |
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[1422] | 33 | typedef UndirSmartGraph Graph; |
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| 34 | typedef Graph::Node Node; |
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| 35 | typedef Graph::NodeIt NodeIt; |
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| 36 | typedef Graph::UndirEdge UndirEdge; |
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| 37 | typedef Graph::IncEdgeIt IncEdgeIt; |
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| 38 | |
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[1683] | 39 | std::cout << "Six coloring of a plan graph" << std::endl; |
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| 40 | std::cout << "Input file: coloring.lgf" << std::endl; |
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| 41 | std::cout << "Output file: coloring.eps" << std::endl; |
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| 42 | |
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[1422] | 43 | Graph graph; |
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| 44 | |
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[1683] | 45 | UndirGraphReader<Graph> reader("coloring.lgf", graph); |
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[1422] | 46 | Graph::NodeMap<xy<double> > coords(graph); |
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| 47 | reader.readNodeMap("coords", coords); |
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| 48 | |
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| 49 | reader.run(); |
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| 50 | |
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| 51 | Graph::NodeMap<int> color(graph, -2); |
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| 52 | |
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| 53 | Graph::NodeMap<int> heapMap(graph, -1); |
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| 54 | BinHeap<Node, int, Graph::NodeMap<int> > heap(heapMap); |
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| 55 | |
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| 56 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 57 | heap.push(it, countOutEdges(graph, it)); |
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| 58 | } |
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| 59 | |
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| 60 | vector<Node> order; |
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| 61 | |
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| 62 | while (!heap.empty()) { |
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| 63 | Node node = heap.top(); |
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| 64 | heap.pop(); |
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| 65 | color[node] = -1; |
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| 66 | order.push_back(node); |
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| 67 | for (IncEdgeIt it(graph, node); it != INVALID; ++it) { |
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| 68 | Node target = graph.runningNode(it); |
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| 69 | if (color[target] == -2) { |
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| 70 | heap.decrease(target, heap[target] - 1); |
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| 71 | } |
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| 72 | } |
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| 73 | } |
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| 74 | |
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| 75 | for (int i = order.size() - 1; i >= 0; --i) { |
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| 76 | set<int> forbidden; |
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| 77 | for (IncEdgeIt it(graph, order[i]); it != INVALID; ++it) { |
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| 78 | Node target = graph.runningNode(it); |
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| 79 | if (color[target] != -1) { |
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| 80 | forbidden.insert(color[target]); |
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| 81 | } |
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| 82 | } |
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| 83 | int current = 0; |
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| 84 | while (forbidden.find(current) != forbidden.end()) ++current; |
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| 85 | color[order[i]] = current; |
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| 86 | } |
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| 87 | |
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| 88 | ColorSet colorSet; |
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| 89 | |
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[1683] | 90 | graphToEps(graph, "coloring.eps"). |
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| 91 | title("Six Colored Plan Graph").copyright("(C) 2005 LEMON Project"). |
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[1422] | 92 | coords(coords).nodeColors(composeMap(colorSet, color)). |
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[1683] | 93 | nodeScale(5.0).scaleToA4().run(); |
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[1422] | 94 | |
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| 95 | return 0; |
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| 96 | } |
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