# HG changeset patch
# User jacint
# Date 1075474571 0
# Node ID e125f12784e2e82d2886f4e1996c85677e6baf0e
# Parent f00a4f7e21498f1ad69dccfc5ba0f46e837d6f1d
*** empty log message ***
diff -r f00a4f7e2149 -r e125f12784e2 src/work/dijkstra.hh
--- a/src/work/dijkstra.hh Fri Jan 30 14:55:10 2004 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,192 +0,0 @@
-/*
- *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 f00a4f7e2149 -r e125f12784e2 src/work/jacint/dijkstra.hh
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/jacint/dijkstra.hh Fri Jan 30 14:56:11 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 f00a4f7e2149 -r e125f12784e2 src/work/jacint/reverse_bfs.hh
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/jacint/reverse_bfs.hh Fri Jan 30 14:56:11 2004 +0000
@@ -0,0 +1,94 @@
+/*
+reverse_bfs
+by jacint
+Performs a bfs on the out edges. It does not count predecessors,
+only the distances, but one can easily modify it to know the pred as well.
+
+Constructor:
+
+reverse_bfs(graph_type& G, node_iterator t)
+
+
+
+Member functions:
+
+void run(): runs a reverse bfs from t
+
+ The following function should be used after run() was already run.
+
+int dist(node_iterator v) : returns the distance from v to t. It is the number of nodes if t is not reachable from v.
+
+*/
+#ifndef REVERSE_BFS_HH
+#define REVERSE_BFS_HH
+
+#include <queue>
+
+#include <marci_graph_traits.hh>
+#include <marci_property_vector.hh>
+
+
+
+namespace marci {
+
+ template <typename graph_type>
+ class reverse_bfs {
+ 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;
+
+
+ graph_type& G;
+ node_iterator t;
+// node_property_vector<graph_type, edge_iterator> pred;
+ node_property_vector<graph_type, int> distance;
+
+
+ public :
+
+ /*
+ The distance of the nodes is n, except t for which it is 0.
+ */
+ reverse_bfs(graph_type& _G, node_iterator _t) : G(_G), t(_t), distance(G, number_of(G.first_node())) {
+ distance.put(t,0);
+ }
+
+ void run() {
+
+ node_property_vector<graph_type, bool> reached(G, false);
+ reached.put(t, true);
+
+ std::queue<node_iterator> bfs_queue;
+ bfs_queue.push(t);
+
+ while (!bfs_queue.empty()) {
+
+ node_iterator v=bfs_queue.front();
+ bfs_queue.pop();
+
+ for(in_edge_iterator e=G.first_in_edge(v); e.valid(); ++e) {
+ node_iterator w=G.tail(e);
+ if (!reached.get(w)) {
+ bfs_queue.push(w);
+ distance.put(w, distance.get(v)+1);
+ reached.put(w, true);
+ }
+ }
+ }
+ }
+
+
+
+ int dist(node_iterator v) {
+ return distance.get(v);
+ }
+
+
+ };
+
+} // namespace marci
+
+#endif //REVERSE_BFS_HH
+
+
diff -r f00a4f7e2149 -r e125f12784e2 src/work/preflow_push_hl.hh
--- a/src/work/preflow_push_hl.hh Fri Jan 30 14:55:10 2004 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,320 +0,0 @@
-/*
-preflow_push_hl.hh
-by jacint.
-Runs the highest label variant of the preflow push algorithm with
-running time O(n^2\sqrt(m)).
-
-Member functions:
-
-void run() : runs the algorithm
-
- The following functions should be used after run() was already run.
-
-T maxflow() : returns the value of a maximum flow
-
-T flowonedge(edge_iterator e) : for a fixed maximum flow x it returns x(e)
-
-edge_property_vector<graph_type, T> allflow() : returns the fixed maximum flow x
-
-node_property_vector<graph_type, bool> mincut() : returns a
- characteristic vector of a minimum cut. (An empty level
- in the algorithm gives a minimum cut.)
-*/
-
-#ifndef PREFLOW_PUSH_HL_HH
-#define PREFLOW_PUSH_HL_HH
-
-#include <algorithm>
-#include <vector>
-#include <stack>
-
-#include <marci_graph_traits.hh>
-#include <marci_property_vector.hh>
-#include <reverse_bfs.hh>
-
-namespace marci {
-
- template <typename graph_type, typename T>
- class preflow_push_hl {
-
- 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>::out_edge_iterator out_edge_iterator;
- typedef typename graph_traits<graph_type>::in_edge_iterator in_edge_iterator;
- typedef typename graph_traits<graph_type>::each_edge_iterator each_edge_iterator;
-
-
- graph_type& G;
- node_iterator s;
- node_iterator t;
- edge_property_vector<graph_type, T> flow;
- edge_property_vector<graph_type, T>& capacity;
- T value;
- node_property_vector<graph_type, bool> mincutvector;
-
-
- public:
-
- preflow_push_hl(graph_type& _G, node_iterator _s, node_iterator _t, edge_property_vector<graph_type, T>& _capacity) : G(_G), s(_s), t(_t), flow(_G, 0), capacity(_capacity), mincutvector(_G, true) { }
-
-
-
-
- /*
- The run() function runs the highest label preflow-push,
- running time: O(n^2\sqrt(m))
- */
- void run() {
-
- node_property_vector<graph_type, int> level(G); //level of node
- node_property_vector<graph_type, T> excess(G); //excess of node
-
- int n=number_of(G.first_node()); //number of nodes
- int b=n;
- /*b is a bound on the highest level of an active node. In the beginning it is at most n-2.*/
-
- std::vector<std::stack<node_iterator> > stack(2*n-1); //Stack of the active nodes in level i.
-
-
-
-
- /*Reverse_bfs from t, to find the starting level.*/
-
- reverse_bfs<list_graph> bfs(G, t);
- bfs.run();
- for(each_node_iterator v=G.first_node(); v.valid(); ++v) {
- level.put(v, bfs.dist(v));
- //std::cout << "the level of " << v << " is " << bfs.dist(v);
- }
-
- /*The level of s is fixed to n*/
- level.put(s,n);
-
-
-
-
-
- /* Starting flow. It is everywhere 0 at the moment. */
-
- for(out_edge_iterator i=G.first_out_edge(s); i.valid(); ++i)
- {
- node_iterator w=G.head(i);
- flow.put(i, capacity.get(i));
- stack[bfs.dist(w)].push(w);
- excess.put(w, capacity.get(i));
- }
-
-
- /*
- End of preprocessing
- */
-
-
-
- /*
- Push/relabel on the highest level active nodes.
- */
-
- /*While there exists active node.*/
- while (b) {
-
- /*We decrease the bound if there is no active node of level b.*/
- if (stack[b].empty()) {
- --b;
- } else {
-
- node_iterator w=stack[b].top(); //w is the highest label active node.
- stack[b].pop(); //We delete w from the stack.
-
- int newlevel=2*n-2; //In newlevel we maintain the next level of w.
-
- for(out_edge_iterator e=G.first_out_edge(w); e.valid(); ++e) {
- node_iterator v=G.head(e);
- /*e is the edge wv.*/
-
- if (flow.get(e)<capacity.get(e)) {
- /*e is an edge of the residual graph */
-
- if(level.get(w)==level.get(v)+1) {
- /*Push is allowed now*/
-
- if (capacity.get(e)-flow.get(e) > excess.get(w)) {
- /*A nonsaturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- flow.put(e, flow.get(e)+excess.get(w));
- excess.put(v, excess.get(v)+excess.get(w));
- excess.put(w,0);
- //std::cout << w << " " << v <<" elore elen nonsat pump " << std::endl;
- break;
- } else {
- /*A saturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- excess.put(v, excess.get(v)+capacity.get(e)-flow.get(e));
- excess.put(w, excess.get(w)-capacity.get(e)+flow.get(e));
- flow.put(e, capacity.get(e));
- //std::cout << w<<" " <<v<<" elore elen sat pump " << std::endl;
- if (excess.get(w)==0) break;
- /*If w is not active any more, then we go on to the next node.*/
-
- } // if (capacity.get(e)-flow.get(e) > excess.get(w))
- } // if(level.get(w)==level.get(v)+1)
-
- else {newlevel = newlevel < level.get(v) ? newlevel : level.get(v);}
-
- } //if (flow.get(e)<capacity.get(e))
-
- } //for(out_edge_iterator e=G.first_out_edge(w); e.valid(); ++e)
-
-
-
- for(in_edge_iterator e=G.first_in_edge(w); e.valid(); ++e) {
- node_iterator v=G.tail(e);
- /*e is the edge vw.*/
-
- if (excess.get(w)==0) break;
- /*It may happen, that w became inactive in the first for cycle.*/
- if(flow.get(e)>0) {
- /*e is an edge of the residual graph */
-
- if(level.get(w)==level.get(v)+1) {
- /*Push is allowed now*/
-
- if (flow.get(e) > excess.get(w)) {
- /*A nonsaturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- flow.put(e, flow.get(e)-excess.get(w));
- excess.put(v, excess.get(v)+excess.get(w));
- excess.put(w,0);
- //std::cout << v << " " << w << " vissza elen nonsat pump " << std::endl;
- break;
- } else {
- /*A saturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- excess.put(v, excess.get(v)+flow.get(e));
- excess.put(w, excess.get(w)-flow.get(e));
- flow.put(e,0);
- //std::cout << v <<" " << w << " vissza elen sat pump " << std::endl;
- if (excess.get(w)==0) { break;}
- } //if (flow.get(e) > excess.get(v))
- } //if(level.get(w)==level.get(v)+1)
-
- else {newlevel = newlevel < level.get(v) ? newlevel : level.get(v);}
-
-
- } //if (flow.get(e)>0)
-
- } //for
-
-
- if (excess.get(w)>0) {
- level.put(w,++newlevel);
- stack[newlevel].push(w);
- b=newlevel;
- //std::cout << "The new level of " << w << " is "<< newlevel <<std::endl;
- }
-
-
- } //else
-
- } //while(b)
-
- value = excess.get(t);
- /*Max flow value.*/
-
-
-
-
- } //void run()
-
-
-
-
-
- /*
- Returns the maximum value of a flow.
- */
-
- T maxflow() {
- return value;
- }
-
-
-
- /*
- For the maximum flow x found by the algorithm, it returns the flow value on edge e, i.e. x(e).
- */
-
- T flowonedge(edge_iterator e) {
- return flow.get(e);
- }
-
-
-
- /*
- Returns the maximum flow x found by the algorithm.
- */
-
- edge_property_vector<graph_type, T> allflow() {
- return flow;
- }
-
-
-
- /*
- Returns a minimum cut by using a reverse bfs from t in the residual graph.
- */
-
- node_property_vector<graph_type, bool> mincut() {
-
- std::queue<node_iterator> queue;
-
- mincutvector.put(t,false);
- queue.push(t);
-
- while (!queue.empty()) {
- node_iterator w=queue.front();
- queue.pop();
-
- for(in_edge_iterator e=G.first_in_edge(w) ; e.valid(); ++e) {
- node_iterator v=G.tail(e);
- if (mincutvector.get(v) && flow.get(e) < capacity.get(e) ) {
- queue.push(v);
- mincutvector.put(v, false);
- }
- } // for
-
- for(out_edge_iterator e=G.first_out_edge(w) ; e.valid(); ++e) {
- node_iterator v=G.head(e);
- if (mincutvector.get(v) && flow.get(e) > 0 ) {
- queue.push(v);
- mincutvector.put(v, false);
- }
- } // for
-
- }
-
- return mincutvector;
-
- }
-
-
- };
-}//namespace marci
-#endif
-
-
-
-
diff -r f00a4f7e2149 -r e125f12784e2 src/work/preflow_push_max_flow.hh
--- a/src/work/preflow_push_max_flow.hh Fri Jan 30 14:55:10 2004 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,315 +0,0 @@
-/*
-preflow_push_max_flow_hh
-by jacint.
-Runs a preflow push algorithm with the modification,
-that we do not push on nodes with level at least n.
-Moreover, if a level gets empty, we put all nodes above that
-level to level n. Hence, in the end, we arrive at a maximum preflow
-with value of a max flow value. An empty level gives a minimum cut.
-
-Member functions:
-
-void run() : runs the algorithm
-
- The following functions should be used after run() was already run.
-
-T maxflow() : returns the value of a maximum flow
-
-node_property_vector<graph_type, bool> mincut(): returns a
- characteristic vector of a minimum cut.
-*/
-
-#ifndef PREFLOW_PUSH_MAX_FLOW_HH
-#define PREFLOW_PUSH_MAX_FLOW_HH
-
-#include <algorithm>
-#include <vector>
-#include <stack>
-
-#include <marci_list_graph.hh>
-#include <marci_graph_traits.hh>
-#include <marci_property_vector.hh>
-#include <reverse_bfs.hh>
-
-
-namespace marci {
-
- template <typename graph_type, typename T>
- class preflow_push_max_flow {
-
- typedef typename graph_traits<graph_type>::node_iterator node_iterator;
- typedef typename graph_traits<graph_type>::each_node_iterator each_node_iterator;
- typedef typename graph_traits<graph_type>::out_edge_iterator out_edge_iterator;
- typedef typename graph_traits<graph_type>::in_edge_iterator in_edge_iterator;
-
- graph_type& G;
- node_iterator s;
- node_iterator t;
- edge_property_vector<graph_type, T>& capacity;
- T value;
- node_property_vector<graph_type, bool> mincutvector;
-
-
-
- public:
-
- preflow_push_max_flow(graph_type& _G, node_iterator _s, node_iterator _t, edge_property_vector<graph_type, T>& _capacity) : G(_G), s(_s), t(_t), capacity(_capacity), mincutvector(_G, false) { }
-
-
- /*
- The run() function runs a modified version of the highest label preflow-push, which only
- finds a maximum preflow, hence giving the value of a maximum flow.
- */
- void run() {
-
- edge_property_vector<graph_type, T> flow(G, 0); //the flow value, 0 everywhere
- node_property_vector<graph_type, int> level(G); //level of node
- node_property_vector<graph_type, T> excess(G); //excess of node
-
- int n=number_of(G.first_node()); //number of nodes
- int b=n-2;
- /*b is a bound on the highest level of an active node. In the beginning it is at most n-2.*/
-
- std::vector<int> numb(n); //The number of nodes on level i < n.
-
- std::vector<std::stack<node_iterator> > stack(2*n-1); //Stack of the active nodes in level i.
-
-
-
- /*Reverse_bfs from t, to find the starting level.*/
-
- reverse_bfs<list_graph> bfs(G, t);
- bfs.run();
- for(each_node_iterator v=G.first_node(); v.valid(); ++v)
- {
- int dist=bfs.dist(v);
- level.put(v, dist);
- ++numb[dist];
- }
-
- /*The level of s is fixed to n*/
- level.put(s,n);
-
-
- /* Starting flow. It is everywhere 0 at the moment. */
-
- for(out_edge_iterator i=G.first_out_edge(s); i.valid(); ++i)
- {
- node_iterator w=G.head(i);
- flow.put(i, capacity.get(i));
- stack[bfs.dist(w)].push(w);
- excess.put(w, capacity.get(i));
- }
-
-
- /*
- End of preprocessing
- */
-
-
-
-
- /*
- Push/relabel on the highest level active nodes.
- */
-
- /*While there exists an active node.*/
- while (b) {
-
- /*We decrease the bound if there is no active node of level b.*/
- if (stack[b].empty()) {
- --b;
- } else {
-
- node_iterator w=stack[b].top(); //w is the highest label active node.
- stack[b].pop(); //We delete w from the stack.
-
- int newlevel=2*n-2; //In newlevel we maintain the next level of w.
-
- for(out_edge_iterator e=G.first_out_edge(w); e.valid(); ++e) {
- node_iterator v=G.head(e);
- /*e is the edge wv.*/
-
- if (flow.get(e)<capacity.get(e)) {
- /*e is an edge of the residual graph */
-
- if(level.get(w)==level.get(v)+1) {
- /*Push is allowed now*/
-
- if (capacity.get(e)-flow.get(e) > excess.get(w)) {
- /*A nonsaturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- flow.put(e, flow.get(e)+excess.get(w));
- excess.put(v, excess.get(v)+excess.get(w));
- excess.put(w,0);
- //std::cout << w << " " << v <<" elore elen nonsat pump " << std::endl;
- break;
- } else {
- /*A saturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- excess.put(v, excess.get(v)+capacity.get(e)-flow.get(e));
- excess.put(w, excess.get(w)-capacity.get(e)+flow.get(e));
- flow.put(e, capacity.get(e));
- //std::cout << w <<" " << v <<" elore elen sat pump " << std::endl;
- if (excess.get(w)==0) break;
- /*If w is not active any more, then we go on to the next node.*/
-
- } // if (capacity.get(e)-flow.get(e) > excess.get(w))
- } // if (level.get(w)==level.get(v)+1)
-
- else {newlevel = newlevel < level.get(v) ? newlevel : level.get(v);}
-
- } //if (flow.get(e)<capacity.get(e))
-
- } //for(out_edge_iterator e=G.first_out_edge(w); e.valid(); ++e)
-
-
-
- for(in_edge_iterator e=G.first_in_edge(w); e.valid(); ++e) {
- node_iterator v=G.tail(e);
- /*e is the edge vw.*/
-
- if (excess.get(w)==0) break;
- /*It may happen, that w became inactive in the first 'for' cycle.*/
-
- if(flow.get(e)>0) {
- /*e is an edge of the residual graph */
-
- if(level.get(w)==level.get(v)+1) {
- /*Push is allowed now*/
-
- if (flow.get(e) > excess.get(w)) {
- /*A nonsaturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- flow.put(e, flow.get(e)-excess.get(w));
- excess.put(v, excess.get(v)+excess.get(w));
- excess.put(w,0);
- //std::cout << v << " " << w << " vissza elen nonsat pump " << std::endl;
- break;
- } else {
- /*A saturating push.*/
-
- if (excess.get(v)==0 && v != s) stack[level.get(v)].push(v);
- /*v becomes active.*/
-
- flow.put(e,0);
- excess.put(v, excess.get(v)+flow.get(e));
- excess.put(w, excess.get(w)-flow.get(e));
- //std::cout << v <<" " << w << " vissza elen sat pump " << std::endl;
- if (excess.get(w)==0) { break;}
- } //if (flow.get(e) > excess.get(v))
- } //if(level.get(w)==level.get(v)+1)
-
- else {newlevel = newlevel < level.get(v) ? newlevel : level.get(v);}
- //std::cout << "Leveldecrease of node " << w << " to " << newlevel << std::endl;
-
- } //if (flow.get(e)>0)
-
- } //for in-edge
-
-
-
-
- /*
- Relabel
- */
- if (excess.get(w)>0) {
- /*Now newlevel <= n*/
-
- int l=level.get(w); //l is the old level of w.
- --numb[l];
-
- if (newlevel == n) {
- level.put(w,n);
-
- } else {
-
- if (numb[l]) {
- /*If the level of w remains nonempty.*/
-
- level.put(w,++newlevel);
- ++numb[newlevel];
- stack[newlevel].push(w);
- b=newlevel;
- } else {
- /*If the level of w gets empty.*/
-
- for (each_node_iterator v=G.first_node() ; v.valid() ; ++v) {
- if (level.get(v) >= l ) {
- level.put(v,n);
- }
- }
-
- for (int i=l+1 ; i!=n ; ++i) numb[i]=0;
- } //if (numb[l])
-
- } // if (newlevel = n)
-
- } // if (excess.get(w)>0)
-
-
- } //else
-
- } //while(b)
-
- value=excess.get(t);
- /*Max flow value.*/
-
-
-
- /*
- We find an empty level, e. The nodes above this level give
- a minimum cut.
- */
-
- int e=1;
-
- while(e) {
- if(numb[e]) ++e;
- else break;
- }
- for (each_node_iterator v=G.first_node(); v.valid(); ++v) {
- if (level.get(v) > e) mincutvector.put(v, true);
- }
-
-
- } // void run()
-
-
-
- /*
- Returns the maximum value of a flow.
- */
-
- T maxflow() {
- return value;
- }
-
-
-
- /*
- Returns a minimum cut.
- */
-
- node_property_vector<graph_type, bool> mincut() {
- return mincutvector;
- }
-
-
- };
-}//namespace marci
-#endif
-
-
-
-
-
diff -r f00a4f7e2149 -r e125f12784e2 src/work/reverse_bfs.hh
--- a/src/work/reverse_bfs.hh Fri Jan 30 14:55:10 2004 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,94 +0,0 @@
-/*
-reverse_bfs
-by jacint
-Performs a bfs on the out edges. It does not count predecessors,
-only the distances, but one can easily modify it to know the pred as well.
-
-Constructor:
-
-reverse_bfs(graph_type& G, node_iterator t)
-
-
-
-Member functions:
-
-void run(): runs a reverse bfs from t
-
- The following function should be used after run() was already run.
-
-int dist(node_iterator v) : returns the distance from v to t. It is the number of nodes if t is not reachable from v.
-
-*/
-#ifndef REVERSE_BFS_HH
-#define REVERSE_BFS_HH
-
-#include <queue>
-
-#include <marci_graph_traits.hh>
-#include <marci_property_vector.hh>
-
-
-
-namespace marci {
-
- template <typename graph_type>
- class reverse_bfs {
- 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;
-
-
- graph_type& G;
- node_iterator t;
-// node_property_vector<graph_type, edge_iterator> pred;
- node_property_vector<graph_type, int> distance;
-
-
- public :
-
- /*
- The distance of the nodes is n, except t for which it is 0.
- */
- reverse_bfs(graph_type& _G, node_iterator _t) : G(_G), t(_t), distance(G, number_of(G.first_node())) {
- distance.put(t,0);
- }
-
- void run() {
-
- node_property_vector<graph_type, bool> reached(G, false);
- reached.put(t, true);
-
- std::queue<node_iterator> bfs_queue;
- bfs_queue.push(t);
-
- while (!bfs_queue.empty()) {
-
- node_iterator v=bfs_queue.front();
- bfs_queue.pop();
-
- for(in_edge_iterator e=G.first_in_edge(v); e.valid(); ++e) {
- node_iterator w=G.tail(e);
- if (!reached.get(w)) {
- bfs_queue.push(w);
- distance.put(w, distance.get(v)+1);
- reached.put(w, true);
- }
- }
- }
- }
-
-
-
- int dist(node_iterator v) {
- return distance.get(v);
- }
-
-
- };
-
-} // namespace marci
-
-#endif //REVERSE_BFS_HH
-
-