Primitive Dijkstra with stl priority queue. flow_test.cc is for testing flows and Dijkstra.
1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/work/dijkstra.hh Fri Jan 23 22:26:13 2004 +0000
1.3 @@ -0,0 +1,192 @@
1.4 +/*
1.5 + *dijkstra
1.6 + *by jacint
1.7 + *Performs Dijkstra's algorithm from node s.
1.8 + *
1.9 + *Constructor:
1.10 + *
1.11 + *dijkstra(graph_type& G, node_iterator s, edge_property_vector& distance)
1.12 + *
1.13 + *
1.14 + *
1.15 + *Member functions:
1.16 + *
1.17 + *void run()
1.18 + *
1.19 + * The following function should be used after run() was already run.
1.20 + *
1.21 + *
1.22 + *T dist(node_iterator v) : returns the distance from s to v.
1.23 + * It is 0 if v is not reachable from s.
1.24 + *
1.25 + *
1.26 + *edge_iterator pred(node_iterator v)
1.27 + * Returns the last edge of a shortest s-v path.
1.28 + * Returns an invalid iterator if v=s or v is not
1.29 + * reachable from s.
1.30 + *
1.31 + *
1.32 + *bool reach(node_iterator v) : true if v is reachable from s
1.33 + *
1.34 + *
1.35 + *
1.36 + *
1.37 + *
1.38 + *Problems:
1.39 + *
1.40 + *Heap implementation is needed, because the priority queue of stl
1.41 + *does not have a mathod for key-decrease, so we had to use here a
1.42 + *g\'any solution.
1.43 + *
1.44 + *The implementation of infinity would be desirable, see after line 100.
1.45 + */
1.46 +
1.47 +#ifndef DIJKSTRA_HH
1.48 +#define DIJKSTRA_HH
1.49 +
1.50 +#include <queue>
1.51 +#include <algorithm>
1.52 +
1.53 +#include <marci_graph_traits.hh>
1.54 +#include <marci_property_vector.hh>
1.55 +
1.56 +
1.57 +namespace std {
1.58 + namespace marci {
1.59 +
1.60 +
1.61 +
1.62 +
1.63 +
1.64 + template <typename graph_type, typename T>
1.65 + class dijkstra{
1.66 + typedef typename graph_traits<graph_type>::node_iterator node_iterator;
1.67 + typedef typename graph_traits<graph_type>::edge_iterator edge_iterator;
1.68 + typedef typename graph_traits<graph_type>::each_node_iterator each_node_iterator;
1.69 + typedef typename graph_traits<graph_type>::in_edge_iterator in_edge_iterator;
1.70 + typedef typename graph_traits<graph_type>::out_edge_iterator out_edge_iterator;
1.71 +
1.72 +
1.73 + graph_type& G;
1.74 + node_iterator s;
1.75 + node_property_vector<graph_type, edge_iterator> predecessor;
1.76 + node_property_vector<graph_type, T> distance;
1.77 + edge_property_vector<graph_type, T> length;
1.78 + node_property_vector<graph_type, bool> reached;
1.79 +
1.80 + public :
1.81 +
1.82 + /*
1.83 + The distance of all the nodes is 0.
1.84 + */
1.85 + dijkstra(graph_type& _G, node_iterator _s, edge_property_vector<graph_type, T>& _length) :
1.86 + G(_G), s(_s), predecessor(G, 0), distance(G, 0), length(_length), reached(G, false) { }
1.87 +
1.88 +
1.89 +
1.90 + /*By Misi.*/
1.91 + struct node_dist_comp
1.92 + {
1.93 + node_property_vector<graph_type, T> &d;
1.94 + node_dist_comp(node_property_vector<graph_type, T> &_d) : d(_d) {}
1.95 +
1.96 + bool operator()(const node_iterator& u, const node_iterator& v) const
1.97 + { return d.get(u) < d.get(v); }
1.98 + };
1.99 +
1.100 +
1.101 +
1.102 + void run() {
1.103 +
1.104 + node_property_vector<graph_type, bool> scanned(G, false);
1.105 + std::priority_queue<node_iterator, vector<node_iterator>, node_dist_comp>
1.106 + heap(( node_dist_comp(distance) ));
1.107 +
1.108 + heap.push(s);
1.109 + reached.put(s, true);
1.110 +
1.111 + while (!heap.empty()) {
1.112 +
1.113 + node_iterator v=heap.top();
1.114 + heap.pop();
1.115 +
1.116 +
1.117 + if (!scanned.get(v)) {
1.118 +
1.119 + for(out_edge_iterator e=G.first_out_edge(v); e.valid(); ++e) {
1.120 + node_iterator w=G.head(e);
1.121 +
1.122 + if (!scanned.get(w)) {
1.123 + if (!reached.get(w)) {
1.124 + reached.put(w,true);
1.125 + distance.put(w, distance.get(v)-length.get(e));
1.126 + predecessor.put(w,e);
1.127 + } else if (distance.get(v)-length.get(e)>distance.get(w)) {
1.128 + distance.put(w, distance.get(v)-length.get(e));
1.129 + predecessor.put(w,e);
1.130 + }
1.131 +
1.132 + heap.push(w);
1.133 +
1.134 + }
1.135 +
1.136 + }
1.137 + scanned.put(v,true);
1.138 +
1.139 + } // if (!scanned.get(v))
1.140 +
1.141 +
1.142 +
1.143 + } // while (!heap.empty())
1.144 +
1.145 +
1.146 + } //void run()
1.147 +
1.148 +
1.149 +
1.150 +
1.151 +
1.152 + /*
1.153 + *Returns the distance of the node v.
1.154 + *It is 0 for the root and for the nodes not
1.155 + *reachable form the root.
1.156 + */
1.157 + T dist(node_iterator v) {
1.158 + return -distance.get(v);
1.159 + }
1.160 +
1.161 +
1.162 +
1.163 + /*
1.164 + * Returns the last edge of a shortest s-v path.
1.165 + * Returns an invalid iterator if v=root or v is not
1.166 + * reachable from the root.
1.167 + */
1.168 + edge_iterator pred(node_iterator v) {
1.169 + if (v!=s) { return predecessor.get(v);}
1.170 + else {return edge_iterator();}
1.171 + }
1.172 +
1.173 +
1.174 +
1.175 + bool reach(node_iterator v) {
1.176 + return reached.get(v);
1.177 + }
1.178 +
1.179 +
1.180 +
1.181 +
1.182 +
1.183 +
1.184 +
1.185 +
1.186 +
1.187 + };// class dijkstra
1.188 +
1.189 +
1.190 +
1.191 + } // namespace marci
1.192 +}
1.193 +#endif //DIJKSTRA_HH
1.194 +
1.195 +
2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
2.2 +++ b/src/work/flow_test.cc Fri Jan 23 22:26:13 2004 +0000
2.3 @@ -0,0 +1,247 @@
2.4 +#include <iostream>
2.5 +#include <vector>
2.6 +#include <string>
2.7 +
2.8 +#include <marci_list_graph.hh>
2.9 +#include <marci_graph_traits.hh>
2.10 +#include <marci_property_vector.hh>
2.11 +#include <preflow_push_hl.hh>
2.12 +#include <preflow_push_max_flow.hh>
2.13 +#include <reverse_bfs.hh>
2.14 +#include <dijkstra.hh>
2.15 +
2.16 +using namespace marci;
2.17 +
2.18 +
2.19 +int main (int, char*[])
2.20 +{
2.21 + typedef graph_traits<list_graph>::node_iterator node_iterator;
2.22 + typedef graph_traits<list_graph>::edge_iterator edge_iterator;
2.23 + typedef graph_traits<list_graph>::each_node_iterator each_node_iterator;
2.24 + typedef graph_traits<list_graph>::each_edge_iterator each_edge_iterator;
2.25 + typedef graph_traits<list_graph>::out_edge_iterator out_edge_iterator;
2.26 + typedef graph_traits<list_graph>::in_edge_iterator in_edge_iterator;
2.27 + typedef graph_traits<list_graph>::sym_edge_iterator sym_edge_iterator;
2.28 +
2.29 + list_graph flow_test;
2.30 +
2.31 + //Ahuja könyv példája, maxflowvalue=13
2.32 + node_iterator s=flow_test.add_node();
2.33 + node_iterator v1=flow_test.add_node();
2.34 + node_iterator v2=flow_test.add_node();
2.35 + node_iterator v3=flow_test.add_node();
2.36 + node_iterator v4=flow_test.add_node();
2.37 + node_iterator v5=flow_test.add_node();
2.38 + node_iterator t=flow_test.add_node();
2.39 +
2.40 + node_property_vector<list_graph, std::string> node_name(flow_test);
2.41 + node_name.put(s, "s");
2.42 + node_name.put(v1, "v1");
2.43 + node_name.put(v2, "v2");
2.44 + node_name.put(v3, "v3");
2.45 + node_name.put(v4, "v4");
2.46 + node_name.put(v5, "v5");
2.47 + node_name.put(t, "t");
2.48 +
2.49 + edge_iterator s_v1=flow_test.add_edge(s, v1);
2.50 + edge_iterator s_v2=flow_test.add_edge(s, v2);
2.51 + edge_iterator s_v3=flow_test.add_edge(s, v3);
2.52 + edge_iterator v2_v4=flow_test.add_edge(v2, v4);
2.53 + edge_iterator v2_v5=flow_test.add_edge(v2, v5);
2.54 + edge_iterator v3_v5=flow_test.add_edge(v3, v5);
2.55 + edge_iterator v4_t=flow_test.add_edge(v4, t);
2.56 + edge_iterator v5_t=flow_test.add_edge(v5, t);
2.57 + edge_iterator v2_s=flow_test.add_edge(v2, s);
2.58 +
2.59 + edge_property_vector<list_graph, int> cap(flow_test);
2.60 + cap.put(s_v1, 0);
2.61 + cap.put(s_v2, 10);
2.62 + cap.put(s_v3, 10);
2.63 + cap.put(v2_v4, 5);
2.64 + cap.put(v2_v5, 8);
2.65 + cap.put(v3_v5, 5);
2.66 + cap.put(v4_t, 8);
2.67 + cap.put(v5_t, 8);
2.68 + cap.put(v2_s, 0);
2.69 +
2.70 +
2.71 +
2.72 + //Marci példája, maxflowvalue=23
2.73 + /* node_iterator s=flow_test.add_node();
2.74 + node_iterator v1=flow_test.add_node();
2.75 + node_iterator v2=flow_test.add_node();
2.76 + node_iterator v3=flow_test.add_node();
2.77 + node_iterator v4=flow_test.add_node();
2.78 + node_iterator t=flow_test.add_node();
2.79 + node_iterator w=flow_test.add_node();
2.80 +
2.81 +
2.82 + node_property_vector<list_graph, std::string> node_name(flow_test);
2.83 + node_name.put(s, "s");
2.84 + node_name.put(v1, "v1");
2.85 + node_name.put(v2, "v2");
2.86 + node_name.put(v3, "v3");
2.87 + node_name.put(v4, "v4");
2.88 + node_name.put(t, "t");
2.89 + node_name.put(w, "w");
2.90 +
2.91 + edge_iterator s_v1=flow_test.add_edge(s, v1);
2.92 + edge_iterator s_v2=flow_test.add_edge(s, v2);
2.93 + edge_iterator v1_v2=flow_test.add_edge(v1, v2);
2.94 + edge_iterator v2_v1=flow_test.add_edge(v2, v1);
2.95 + edge_iterator v1_v3=flow_test.add_edge(v1, v3);
2.96 + edge_iterator v3_v2=flow_test.add_edge(v3, v2);
2.97 + edge_iterator v2_v4=flow_test.add_edge(v2, v4);
2.98 + edge_iterator v4_v3=flow_test.add_edge(v4, v3);
2.99 + edge_iterator v3_t=flow_test.add_edge(v3, t);
2.100 + edge_iterator v4_t=flow_test.add_edge(v4, t);
2.101 + edge_iterator v3_v3=flow_test.add_edge(v3, v3);
2.102 + edge_iterator s_w=flow_test.add_edge(s, w);
2.103 + // edge_iterator v2_s=flow_test.add_edge(v2, s);
2.104 +
2.105 +
2.106 +
2.107 + edge_property_vector<list_graph, int> cap(flow_test); //serves as length in dijkstra
2.108 + cap.put(s_v1, 16);
2.109 + cap.put(s_v2, 13);
2.110 + cap.put(v1_v2, 10);
2.111 + cap.put(v2_v1, 4);
2.112 + cap.put(v1_v3, 12);
2.113 + cap.put(v3_v2, 9);
2.114 + cap.put(v2_v4, 14);
2.115 + cap.put(v4_v3, 7);
2.116 + cap.put(v3_t, 20);
2.117 + cap.put(v4_t, 4);
2.118 + cap.put(v3_v3, 4);
2.119 + cap.put(s_w, 4);
2.120 + // cap.put(v2_s, 0);
2.121 +
2.122 +*/
2.123 +
2.124 + //pelda 3, maxflowvalue=4
2.125 + /* node_iterator s=flow_test.add_node();
2.126 + node_iterator v1=flow_test.add_node();
2.127 + node_iterator v2=flow_test.add_node();
2.128 + node_iterator t=flow_test.add_node();
2.129 + node_iterator w=flow_test.add_node();
2.130 +
2.131 + node_property_vector<list_graph, std::string> node_name(flow_test);
2.132 + node_name.put(s, "s");
2.133 + node_name.put(v1, "v1");
2.134 + node_name.put(v2, "v2");
2.135 + node_name.put(t, "t");
2.136 + node_name.put(w, "w");
2.137 +
2.138 + edge_iterator s_v1=flow_test.add_edge(s, v1);
2.139 + edge_iterator v1_v2=flow_test.add_edge(v1, v2);
2.140 + edge_iterator v2_t=flow_test.add_edge(v2, t);
2.141 + edge_iterator v1_v1=flow_test.add_edge(v1, v1);
2.142 + edge_iterator s_w=flow_test.add_edge(s, w);
2.143 +
2.144 +
2.145 + edge_property_vector<list_graph, int> cap(flow_test);
2.146 +
2.147 + cap.put(s_v1, 16);
2.148 + cap.put(v1_v2, 10);
2.149 + cap.put(v2_t, 4);
2.150 + cap.put(v1_v1, 3);
2.151 + cap.put(s_w, 5);
2.152 + */
2.153 +
2.154 +
2.155 +
2.156 +
2.157 + std::cout << "Testing reverse_bfs..." << std::endl;
2.158 +
2.159 + reverse_bfs<list_graph> bfs_test(flow_test, t);
2.160 +
2.161 + bfs_test.run();
2.162 +
2.163 + for (each_node_iterator w=flow_test.first_node(); w.valid(); ++w) {
2.164 + std::cout <<"The distance of " << w << " is " << bfs_test.dist(w) <<std::endl;
2.165 + }
2.166 +
2.167 +
2.168 +
2.169 +
2.170 +
2.171 + std::cout << "Testing preflow_push_hl..." << std::endl;
2.172 +
2.173 + preflow_push_hl<list_graph, int> preflow_push_test(flow_test, s, t, cap);
2.174 +
2.175 + preflow_push_test.run();
2.176 +
2.177 + std::cout << "Maximum flow value is: " << preflow_push_test.maxflow() << "."<<std::endl;
2.178 +
2.179 + std::cout<< "The flow on edge s-v1 is "<< preflow_push_test.flowonedge(s_v1) << "."<<std::endl;
2.180 +
2.181 + edge_property_vector<list_graph, int> flow=preflow_push_test.allflow();
2.182 + for (each_edge_iterator e=flow_test.first_edge(); e.valid(); ++e) {
2.183 + std::cout <<"Flow on edge " << flow_test.tail(e) <<"-" << flow_test.head(e)<< " is " <<flow.get(e) <<std::endl;
2.184 + }
2.185 +
2.186 + std::cout << "A minimum cut: " <<std::endl;
2.187 + node_property_vector<list_graph, bool> mincut=preflow_push_test.mincut();
2.188 +
2.189 + for (each_node_iterator v=flow_test.first_node(); v.valid(); ++v) {
2.190 + if (mincut.get(v)) std::cout <<node_name.get(v)<< " ";
2.191 + }
2.192 +
2.193 + std::cout<<"\n\n"<<std::endl;
2.194 +
2.195 +
2.196 +
2.197 +
2.198 + std::cout << "Testing preflow_push_max_flow..." << std::endl;
2.199 +
2.200 + preflow_push_max_flow<list_graph, int> max_flow_test(flow_test, s, t, cap);
2.201 +
2.202 + max_flow_test.run();
2.203 +
2.204 + std::cout << "Maximum flow value is: " << max_flow_test.maxflow() << "."<< std::endl;
2.205 +
2.206 + std::cout << "A minimum cut: " <<std::endl;
2.207 + node_property_vector<list_graph, bool> mincut2=max_flow_test.mincut();
2.208 +
2.209 + for (each_node_iterator v=flow_test.first_node(); v.valid(); ++v) {
2.210 + if (mincut2.get(v)) std::cout <<node_name.get(v)<< " ";
2.211 + }
2.212 +
2.213 + std::cout << std::endl <<std::endl;
2.214 +
2.215 +
2.216 +
2.217 + std::cout << "Testing dijkstra..." << std::endl;
2.218 +
2.219 + node_iterator root=v2;
2.220 +
2.221 + dijkstra<list_graph, int> dijkstra_test(flow_test, root, cap);
2.222 +
2.223 + dijkstra_test.run();
2.224 +
2.225 + for (each_node_iterator w=flow_test.first_node(); w.valid(); ++w) {
2.226 + if (dijkstra_test.reach(w)) {
2.227 + std::cout <<"The distance of " << w << " is " << dijkstra_test.dist(w);
2.228 + if (dijkstra_test.pred(w).valid()) {
2.229 + std::cout <<", a shortest path from the root ends with edge " << dijkstra_test.pred(w) <<std::endl;
2.230 + } else {
2.231 + std::cout <<", this is the root."<<std::endl; }
2.232 +
2.233 + } else {
2.234 + cout << w << " is not reachable from " << root <<std::endl;
2.235 + }
2.236 + }
2.237 +
2.238 +
2.239 +
2.240 + return 0;
2.241 +}
2.242 +
2.243 +
2.244 +
2.245 +
2.246 +
2.247 +
2.248 +
2.249 +
2.250 +
3.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
3.2 +++ b/src/work/jacint_makefile Fri Jan 23 22:26:13 2004 +0000
3.3 @@ -0,0 +1,9 @@
3.4 +CCFLAGS = -Wall -ansi
3.5 +CXXFLAGS = -Wall -ansi -I. -g
3.6 +CC = g++-3.0
3.7 +
3.8 +flow_test: flow_test.cc marci_list_graph.hh reverse_bfs.hh preflow_push_hl.hh marci_graph_traits.hh marci_property_vector.hh preflow_push_max_flow.hh dijkstra.hh
3.9 + $(CXX) $(CXXFLAGS) -o flow_test flow_test.cc
3.10 +
3.11 +marci_graph_demo: marci_graph_demo.cc marci_graph_traits.hh marci_list_graph.hh marci_property_vector.hh marci_bfs.hh marci_max_flow.hh
3.12 + $(CC) $(CCFLAGS) -I. marci_graph_demo.cc -o marci_graph_demo