1 | #include <vector> |
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2 | |
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3 | #include <lemon/smart_graph.h> |
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4 | #include <lemon/bin_heap.h> |
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5 | #include <lemon/graph_reader.h> |
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6 | #include <lemon/graph_to_eps.h> |
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7 | |
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8 | #include <fstream> |
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9 | #include <iostream> |
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10 | |
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11 | |
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12 | using namespace std; |
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13 | using namespace lemon; |
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14 | |
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15 | int main(int argc, char *argv[]) |
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16 | { |
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17 | if(argc<2) |
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18 | { |
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19 | std::cerr << "USAGE: coloring input_file.lgf" << std::endl; |
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20 | std::cerr << "The file 'input_file.lgf' has to contain a graph in LEMON format together with a nodemap called 'coords' to draw the graph (e.g. sample.lgf is not such a file)." << std::endl; |
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21 | return 0; |
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22 | } |
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23 | |
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24 | |
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25 | //input stream to read the graph from |
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26 | std::ifstream is(argv[1]); |
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27 | |
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28 | typedef UndirSmartGraph Graph; |
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29 | typedef Graph::Node Node; |
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30 | typedef Graph::NodeIt NodeIt; |
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31 | typedef Graph::UndirEdge UndirEdge; |
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32 | typedef Graph::IncEdgeIt IncEdgeIt; |
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33 | |
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34 | Graph graph; |
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35 | |
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36 | UndirGraphReader<Graph> reader(is, graph); |
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37 | Graph::NodeMap<xy<double> > coords(graph); |
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38 | reader.readNodeMap("coords", coords); |
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39 | |
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40 | reader.run(); |
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41 | |
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42 | Graph::NodeMap<int> color(graph, -2); |
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43 | |
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44 | Graph::NodeMap<int> heapMap(graph, -1); |
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45 | BinHeap<Node, int, Graph::NodeMap<int> > heap(heapMap); |
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46 | |
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47 | for (NodeIt it(graph); it != INVALID; ++it) { |
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48 | heap.push(it, countOutEdges(graph, it)); |
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49 | } |
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50 | |
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51 | vector<Node> order; |
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52 | |
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53 | while (!heap.empty()) { |
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54 | Node node = heap.top(); |
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55 | heap.pop(); |
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56 | color[node] = -1; |
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57 | order.push_back(node); |
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58 | for (IncEdgeIt it(graph, node); it != INVALID; ++it) { |
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59 | Node target = graph.runningNode(it); |
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60 | if (color[target] == -2) { |
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61 | heap.decrease(target, heap[target] - 1); |
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62 | } |
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63 | } |
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64 | } |
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65 | |
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66 | for (int i = order.size() - 1; i >= 0; --i) { |
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67 | set<int> forbidden; |
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68 | for (IncEdgeIt it(graph, order[i]); it != INVALID; ++it) { |
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69 | Node target = graph.runningNode(it); |
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70 | if (color[target] != -1) { |
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71 | forbidden.insert(color[target]); |
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72 | } |
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73 | } |
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74 | int current = 0; |
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75 | while (forbidden.find(current) != forbidden.end()) ++current; |
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76 | color[order[i]] = current; |
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77 | } |
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78 | |
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79 | ColorSet colorSet; |
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80 | |
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81 | graphToEps(graph, "six_coloring.eps"). |
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82 | title("Six Colored Graph").copyright("(C) 2005 LEMON Project"). |
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83 | coords(coords).nodeColors(composeMap(colorSet, color)). |
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84 | scaleToA4().run(); |
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85 | |
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86 | return 0; |
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87 | } |
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