# HG changeset patch
# User jacint
# Date 1074896773 0
# Node ID f505c414feb9c509847a170716296673e01e29cc
# Parent  82f6987d6d2e5bf995a5b9c6cbd56e5a2ecb71a9
Primitive Dijkstra with stl priority queue. flow_test.cc is for testing flows and Dijkstra.

diff -r 82f6987d6d2e -r f505c414feb9 src/work/dijkstra.hh
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/dijkstra.hh	Fri Jan 23 22:26:13 2004 +0000
@@ -0,0 +1,192 @@
+/*
+ *dijkstra
+ *by jacint
+ *Performs Dijkstra's algorithm from node s. 
+ *
+ *Constructor: 
+ *
+ *dijkstra(graph_type& G, node_iterator s, edge_property_vector& distance)
+ *
+ *
+ *
+ *Member functions:
+ *
+ *void run()
+ *
+ *  The following function should be used after run() was already run.
+ *
+ *
+ *T dist(node_iterator v) : returns the distance from s to v. 
+ *   It is 0 if v is not reachable from s.
+ *
+ *
+ *edge_iterator pred(node_iterator v)
+ *   Returns the last edge of a shortest s-v path. 
+ *   Returns an invalid iterator if v=s or v is not
+ *   reachable from s.
+ *
+ *
+ *bool reach(node_iterator v) : true if v is reachable from s
+ *
+ *
+ *
+ *
+ *
+ *Problems: 
+ * 
+ *Heap implementation is needed, because the priority queue of stl
+ *does not have a mathod for key-decrease, so we had to use here a 
+ *g\'any solution.
+ * 
+ *The implementation of infinity would be desirable, see after line 100. 
+ */
+
+#ifndef DIJKSTRA_HH
+#define DIJKSTRA_HH
+
+#include <queue>
+#include <algorithm>
+
+#include <marci_graph_traits.hh>
+#include <marci_property_vector.hh>
+
+
+namespace std {
+  namespace marci {
+
+
+
+
+
+    template <typename graph_type, typename T>
+    class dijkstra{
+      typedef typename graph_traits<graph_type>::node_iterator node_iterator;
+      typedef typename graph_traits<graph_type>::edge_iterator edge_iterator;
+      typedef typename graph_traits<graph_type>::each_node_iterator each_node_iterator;
+      typedef typename graph_traits<graph_type>::in_edge_iterator in_edge_iterator;
+      typedef typename graph_traits<graph_type>::out_edge_iterator out_edge_iterator;
+      
+      
+      graph_type& G;
+      node_iterator s;
+      node_property_vector<graph_type, edge_iterator> predecessor;
+      node_property_vector<graph_type, T> distance;
+      edge_property_vector<graph_type, T> length;
+      node_property_vector<graph_type, bool> reached;
+          
+  public :
+
+    /*
+      The distance of all the nodes is 0.
+    */
+    dijkstra(graph_type& _G, node_iterator _s, edge_property_vector<graph_type, T>& _length) : 
+      G(_G), s(_s), predecessor(G, 0), distance(G, 0), length(_length), reached(G, false) { }
+    
+
+      
+      /*By Misi.*/
+      struct node_dist_comp
+      {
+	node_property_vector<graph_type, T> &d;
+	node_dist_comp(node_property_vector<graph_type, T> &_d) : d(_d) {} 
+	
+	bool operator()(const node_iterator& u, const node_iterator& v) const 
+	{ return d.get(u) < d.get(v); }
+      };
+
+
+      
+      void run() {
+	
+	node_property_vector<graph_type, bool> scanned(G, false);
+	std::priority_queue<node_iterator, vector<node_iterator>, node_dist_comp> 
+	  heap(( node_dist_comp(distance) ));
+      
+	heap.push(s);
+	reached.put(s, true);
+
+	while (!heap.empty()) {
+
+	  node_iterator v=heap.top();	
+	  heap.pop();
+
+
+	  if (!scanned.get(v)) {
+	
+	    for(out_edge_iterator e=G.first_out_edge(v); e.valid(); ++e) {
+	      node_iterator w=G.head(e);
+
+	      if (!scanned.get(w)) {
+		if (!reached.get(w)) {
+		  reached.put(w,true);
+		  distance.put(w, distance.get(v)-length.get(e));
+		  predecessor.put(w,e);
+		} else if (distance.get(v)-length.get(e)>distance.get(w)) {
+		  distance.put(w, distance.get(v)-length.get(e));
+		  predecessor.put(w,e);
+		}
+		
+		heap.push(w);
+	      
+	      } 
+
+	    } 
+	    scanned.put(v,true);
+	    
+	  } // if (!scanned.get(v))
+	  
+	  
+	  
+	} // while (!heap.empty())
+
+	
+      } //void run()
+      
+      
+      
+
+
+      /*
+       *Returns the distance of the node v.
+       *It is 0 for the root and for the nodes not
+       *reachable form the root.
+       */      
+      T dist(node_iterator v) {
+	return -distance.get(v);
+      }
+
+
+
+      /*
+       *  Returns the last edge of a shortest s-v path. 
+       *  Returns an invalid iterator if v=root or v is not
+       *  reachable from the root.
+       */      
+      edge_iterator pred(node_iterator v) {
+	if (v!=s) { return predecessor.get(v);}
+	else {return edge_iterator();}
+      }
+     
+
+      
+      bool reach(node_iterator v) {
+	return reached.get(v);
+      }
+
+
+
+
+
+
+
+
+
+    };// class dijkstra
+
+
+
+  } // namespace marci
+}
+#endif //DIJKSTRA_HH
+
+
diff -r 82f6987d6d2e -r f505c414feb9 src/work/flow_test.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/flow_test.cc	Fri Jan 23 22:26:13 2004 +0000
@@ -0,0 +1,247 @@
+#include <iostream>
+#include <vector>
+#include <string>
+
+#include <marci_list_graph.hh>
+#include <marci_graph_traits.hh>
+#include <marci_property_vector.hh>
+#include <preflow_push_hl.hh>
+#include <preflow_push_max_flow.hh>
+#include <reverse_bfs.hh>
+#include <dijkstra.hh>
+
+using namespace marci;
+
+
+int main (int, char*[])
+{
+  typedef graph_traits<list_graph>::node_iterator node_iterator;
+  typedef graph_traits<list_graph>::edge_iterator edge_iterator;
+  typedef graph_traits<list_graph>::each_node_iterator each_node_iterator;
+  typedef graph_traits<list_graph>::each_edge_iterator each_edge_iterator;
+  typedef graph_traits<list_graph>::out_edge_iterator out_edge_iterator;
+  typedef graph_traits<list_graph>::in_edge_iterator in_edge_iterator;
+  typedef graph_traits<list_graph>::sym_edge_iterator sym_edge_iterator;
+
+  list_graph flow_test;
+ 
+    //Ahuja könyv példája, maxflowvalue=13
+  node_iterator s=flow_test.add_node();
+  node_iterator v1=flow_test.add_node();
+  node_iterator v2=flow_test.add_node();
+  node_iterator v3=flow_test.add_node();
+  node_iterator v4=flow_test.add_node();
+  node_iterator v5=flow_test.add_node();
+  node_iterator t=flow_test.add_node();
+  
+  node_property_vector<list_graph, std::string> node_name(flow_test);
+  node_name.put(s, "s");
+  node_name.put(v1, "v1");
+  node_name.put(v2, "v2");
+  node_name.put(v3, "v3");
+  node_name.put(v4, "v4");
+  node_name.put(v5, "v5");
+  node_name.put(t, "t");
+
+  edge_iterator s_v1=flow_test.add_edge(s, v1);
+  edge_iterator s_v2=flow_test.add_edge(s, v2);
+  edge_iterator s_v3=flow_test.add_edge(s, v3);
+  edge_iterator v2_v4=flow_test.add_edge(v2, v4);
+  edge_iterator v2_v5=flow_test.add_edge(v2, v5);
+  edge_iterator v3_v5=flow_test.add_edge(v3, v5);
+  edge_iterator v4_t=flow_test.add_edge(v4, t);
+  edge_iterator v5_t=flow_test.add_edge(v5, t);
+  edge_iterator v2_s=flow_test.add_edge(v2, s);
+  
+  edge_property_vector<list_graph, int> cap(flow_test);  
+  cap.put(s_v1, 0);
+  cap.put(s_v2, 10);
+  cap.put(s_v3, 10);
+  cap.put(v2_v4, 5);
+  cap.put(v2_v5, 8);
+  cap.put(v3_v5, 5);
+  cap.put(v4_t, 8);
+  cap.put(v5_t, 8);
+  cap.put(v2_s, 0);
+
+
+  
+  //Marci példája, maxflowvalue=23
+  /*  node_iterator s=flow_test.add_node();
+  node_iterator v1=flow_test.add_node();
+  node_iterator v2=flow_test.add_node();
+  node_iterator v3=flow_test.add_node();
+  node_iterator v4=flow_test.add_node();
+  node_iterator t=flow_test.add_node();
+  node_iterator w=flow_test.add_node();
+
+  
+  node_property_vector<list_graph, std::string> node_name(flow_test);
+  node_name.put(s, "s");
+  node_name.put(v1, "v1");
+  node_name.put(v2, "v2");
+  node_name.put(v3, "v3");
+  node_name.put(v4, "v4");
+  node_name.put(t, "t");
+  node_name.put(w, "w");
+
+  edge_iterator s_v1=flow_test.add_edge(s, v1);
+  edge_iterator s_v2=flow_test.add_edge(s, v2);
+  edge_iterator v1_v2=flow_test.add_edge(v1, v2);
+  edge_iterator v2_v1=flow_test.add_edge(v2, v1);
+  edge_iterator v1_v3=flow_test.add_edge(v1, v3);
+  edge_iterator v3_v2=flow_test.add_edge(v3, v2);
+  edge_iterator v2_v4=flow_test.add_edge(v2, v4);
+  edge_iterator v4_v3=flow_test.add_edge(v4, v3);
+  edge_iterator v3_t=flow_test.add_edge(v3, t);
+  edge_iterator v4_t=flow_test.add_edge(v4, t);
+  edge_iterator v3_v3=flow_test.add_edge(v3, v3);
+  edge_iterator s_w=flow_test.add_edge(s, w);
+  //  edge_iterator v2_s=flow_test.add_edge(v2, s);
+  
+
+
+  edge_property_vector<list_graph, int> cap(flow_test);  //serves as length in dijkstra
+  cap.put(s_v1, 16);
+  cap.put(s_v2, 13);
+  cap.put(v1_v2, 10);
+  cap.put(v2_v1, 4);
+  cap.put(v1_v3, 12);
+  cap.put(v3_v2, 9);
+  cap.put(v2_v4, 14);
+  cap.put(v4_v3, 7);
+  cap.put(v3_t, 20);
+  cap.put(v4_t, 4);
+  cap.put(v3_v3, 4);
+  cap.put(s_w, 4);
+  //  cap.put(v2_s, 0);
+
+*/
+
+  //pelda 3, maxflowvalue=4
+  /*      node_iterator s=flow_test.add_node();
+  node_iterator v1=flow_test.add_node();
+  node_iterator v2=flow_test.add_node();
+  node_iterator t=flow_test.add_node();
+  node_iterator w=flow_test.add_node();
+  
+  node_property_vector<list_graph, std::string> node_name(flow_test);
+  node_name.put(s, "s");
+  node_name.put(v1, "v1");
+  node_name.put(v2, "v2");
+  node_name.put(t, "t");
+  node_name.put(w, "w");
+
+  edge_iterator s_v1=flow_test.add_edge(s, v1);
+  edge_iterator v1_v2=flow_test.add_edge(v1, v2);
+  edge_iterator v2_t=flow_test.add_edge(v2, t);
+  edge_iterator v1_v1=flow_test.add_edge(v1, v1);
+  edge_iterator s_w=flow_test.add_edge(s, w);
+
+
+  edge_property_vector<list_graph, int> cap(flow_test); 
+    
+  cap.put(s_v1, 16);
+  cap.put(v1_v2, 10);
+  cap.put(v2_t, 4);
+  cap.put(v1_v1, 3);
+  cap.put(s_w, 5);
+  */
+  
+
+
+
+  std::cout << "Testing reverse_bfs..." << std::endl;
+  
+  reverse_bfs<list_graph> bfs_test(flow_test, t);
+
+  bfs_test.run();
+
+  for (each_node_iterator w=flow_test.first_node(); w.valid(); ++w) {
+    std::cout <<"The distance of " << w << " is " << bfs_test.dist(w) <<std::endl;
+    }
+
+
+
+
+
+  std::cout << "Testing preflow_push_hl..." << std::endl;
+  
+  preflow_push_hl<list_graph, int> preflow_push_test(flow_test, s, t, cap);
+
+  preflow_push_test.run();
+
+  std::cout << "Maximum flow value is: " << preflow_push_test.maxflow() << "."<<std::endl;
+
+  std::cout<< "The flow on edge s-v1 is "<< preflow_push_test.flowonedge(s_v1) << "."<<std::endl;
+
+  edge_property_vector<list_graph, int> flow=preflow_push_test.allflow();  
+  for (each_edge_iterator e=flow_test.first_edge(); e.valid(); ++e) {
+    std::cout <<"Flow on edge " << flow_test.tail(e) <<"-" << flow_test.head(e)<< " is " <<flow.get(e) <<std::endl;
+    }
+
+  std::cout << "A minimum cut: " <<std::endl;  
+  node_property_vector<list_graph, bool> mincut=preflow_push_test.mincut();
+
+  for (each_node_iterator v=flow_test.first_node(); v.valid(); ++v) {
+      if (mincut.get(v)) std::cout <<node_name.get(v)<< " ";
+    }
+  
+  std::cout<<"\n\n"<<std::endl;
+
+
+
+
+  std::cout << "Testing preflow_push_max_flow..." << std::endl;
+ 
+  preflow_push_max_flow<list_graph, int> max_flow_test(flow_test, s, t, cap);
+
+  max_flow_test.run();
+
+  std::cout << "Maximum flow value is: " << max_flow_test.maxflow() << "."<< std::endl;
+
+  std::cout << "A minimum cut: " <<std::endl;  
+  node_property_vector<list_graph, bool> mincut2=max_flow_test.mincut();
+
+  for (each_node_iterator v=flow_test.first_node(); v.valid(); ++v) {
+    if (mincut2.get(v)) std::cout <<node_name.get(v)<< " ";
+  }
+  
+  std::cout << std::endl <<std::endl;
+
+
+
+    std::cout << "Testing dijkstra..." << std::endl;
+  
+    node_iterator root=v2;
+
+    dijkstra<list_graph, int> dijkstra_test(flow_test, root, cap);
+
+    dijkstra_test.run();
+
+    for (each_node_iterator w=flow_test.first_node(); w.valid(); ++w) {
+      if (dijkstra_test.reach(w)) {
+      std::cout <<"The distance of " << w << " is " << dijkstra_test.dist(w);
+      if (dijkstra_test.pred(w).valid()) {
+      std::cout <<", a shortest path from the root ends with edge " << dijkstra_test.pred(w) <<std::endl; 
+      } else {
+       std::cout <<", this is the root."<<std::endl; }
+      
+      } else {
+	cout << w << " is not reachable from " << root <<std::endl;
+      }
+    }
+
+
+
+  return 0;
+}
+
+
+
+
+
+
+
+
+
diff -r 82f6987d6d2e -r f505c414feb9 src/work/jacint_makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/jacint_makefile	Fri Jan 23 22:26:13 2004 +0000
@@ -0,0 +1,9 @@
+CCFLAGS = -Wall -ansi
+CXXFLAGS = -Wall -ansi -I. -g
+CC = g++-3.0
+
+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
+	$(CXX) $(CXXFLAGS) -o flow_test flow_test.cc
+
+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
+	$(CC) $(CCFLAGS) -I. marci_graph_demo.cc -o marci_graph_demo