lemon-0.x: comparison src/work/jacint/preflow

equal deleted inserted replaced

-:fe69f506644c
+:d279d62c1bff
 // -*- C++ -*-
 /*
 preflow_hl3.h
 by jacint.
-Runs the highest label variant of the preflow push algorithm with
-running time O(n^2\sqrt(m)), with the felszippantos 'empty level'
+Heuristics:
-and with the two-phase heuristic: if there is no active node of
-level at most n, then we go into phase 1, do a bfs
+suck gap : if there is a gap, then we put all
-from s, and flow the excess back to s.
+nodes reachable from the relabelled node to level n
+2 phase
-In phase 1 we shift everything downwards by n.
+highest label
-'A' is a parameter for the empty_level heuristic
+The constructor runs the algorithm.
-Member functions:
+Members:
-void run() : runs the algorithm
+T maxFlow() : returns the value of a maximum flow
-The following functions should be used after run() was already run.
+T flowOnEdge(EdgeIt e) : for a fixed maximum flow x it returns x(e)
-T maxflow() : returns the value of a maximum flow
+FlowMap Flow() : returns the fixed maximum flow x
-T flowonedge(EdgeIt e) : for a fixed maximum flow x it returns x(e)
+void minCut(CutMap& M) : sets M to the characteristic vector of a
-FlowMap allflow() : returns the fixed maximum flow x
-void mincut(CutMap& M) : sets M to the characteristic vector of a
 minimum cut. M should be a map of bools initialized to false.
-void min_mincut(CutMap& M) : sets M to the characteristic vector of the
+void minMinCut(CutMap& M) : sets M to the characteristic vector of the
 minimum min cut. M should be a map of bools initialized to false.
-void max_mincut(CutMap& M) : sets M to the characteristic vector of the
+void maxMinCut(CutMap& M) : sets M to the characteristic vector of the
 maximum min cut. M should be a map of bools initialized to false.
 */
 #ifndef PREFLOW_HL3_H
 #define PREFLOW_HL3_H
-#define A 1
 #include <vector>
 #include <stack>
 #include <queue>
+#include <time_measure.h> //for test
 namespace hugo {
 template <typename Graph, typename T,
-typename FlowMap=typename Graph::EdgeMap<T>, typename CapMap=typename Graph::EdgeMap<T>,
+typename FlowMap=typename Graph::EdgeMap<T>,
-typename IntMap=typename Graph::NodeMap<int>, typename TMap=typename Graph::NodeMap<T> >
+typename CapMap=typename Graph::EdgeMap<T> >
 class preflow_hl3 {
 typedef typename Graph::NodeIt NodeIt;
 typedef typename Graph::EdgeIt EdgeIt;
 typedef typename Graph::EachNodeIt EachNodeIt;
 CapMap& capacity;
 T value;
 public:
+double time; //for test
 preflow_hl3(Graph& _G, NodeIt _s, NodeIt _t, CapMap& _capacity) :
-G(_G), s(_s), t(_t), flow(_G, 0), capacity(_capacity) { }
+G(_G), s(_s), t(_t), flow(_G, 0), capacity(_capacity) {
-void run() {
 bool phase=0;
 int n=G.nodeNum();
 int b=n-2;
 /*
 	b is a bound on the highest level of the stack.
 	In the beginning it is at most n-2.
 */
-IntMap level(G,n);
+typename Graph::NodeMap<int> level(G,n);
-TMap excess(G);
+typename Graph::NodeMap<T> excess(G);
 std::vector<int> numb(n);
 /*
 	The number of nodes on level i < n. It is
 	initialized to n+1, because of the reverse_bfs-part.
 while ( true ) {
 	if ( b == 0 ) {
 	  if ( phase ) break;
 	  phase=1;
+	  time=currTime();
 	  level.set(s,0);
 	  std::queue<NodeIt> bfs_queue;
 	  bfs_queue.push(s);
 	}
 	if ( stack[b].empty() ) --b;
 	else {
-	  NodeIt w=stack[b].top();        //w is a highest label active node.
+	  NodeIt w=stack[b].top();
 	  stack[b].pop();
 	  int lev=level.get(w);
-	  int exc=excess.get(w);
+	  T exc=excess.get(w);
-	  int newlevel=n;                 //In newlevel we bound the next level of w.
+	  int newlevel=n;          //bound on the next level of w.
 	  for(OutEdgeIt e=G.template first<OutEdgeIt>(w); e.valid(); ++e) {
 	    if ( flow.get(e) == capacity.get(e) ) continue;
 	    NodeIt v=G.head(e);
 	      if ( excess.get(v)==0 && v !=t && v!=s )
 		stack[level.get(v)].push(v);
 	      /*v becomes active.*/
-	      int cap=capacity.get(e);
+	      T cap=capacity.get(e);
-	      int flo=flow.get(e);
+	      T flo=flow.get(e);
-	      int remcap=cap-flo;
+	      T remcap=cap-flo;
 	      if ( remcap >= exc ) {
 		/*A nonsaturating push.*/
 		flow.set(e, flo+exc);
 	      if ( excess.get(v)==0 && v !=t && v!=s )
 		stack[level.get(v)].push(v);
 	      /*v becomes active.*/
-	      int flo=flow.get(e);
+	      T flo=flow.get(e);
 	      if ( flo >= exc ) {
 		/*A nonsaturating push.*/
 		flow.set(e, flo-exc);
 /*
 Returns the maximum value of a flow.
 */
-T maxflow() {
+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).
+For the maximum flow x found by the algorithm,
+it returns the flow value on edge e, i.e. x(e).
 */
-T flowonedge(EdgeIt e) {
+T flowOnEdge(EdgeIt e) {
 return flow.get(e);
 }
 /*
 Returns the maximum flow x found by the algorithm.
 */
-FlowMap allflow() {
+FlowMap Flow() {
 return flow;
 }
 /*
 Returns the minimum min cut, by a bfs from s in the residual graph.
 */
 template<typename CutMap>
-void mincut(CutMap& M) {
+void minCut(CutMap& M) {
 std::queue<NodeIt> queue;
 M.set(s,true);
 queue.push(s);
 Returns the maximum min cut, by a reverse bfs
 from t in the residual graph.
 */
 template<typename CutMap>
-void max_mincut(CutMap& M) {
+void maxMinCut(CutMap& M) {
 std::queue<NodeIt> queue;
 M.set(t,true);
 queue.push(t);
 }
 template<typename CutMap>
-void min_mincut(CutMap& M) {
+void minMinCut(CutMap& M) {
-mincut(M);
+minCut(M);
 }
 };
-}//namespace hugo
+}//namespace
 #endif

changeset 120	576f55fec89e
parent 105	a3c73e9b9b2e