1 | // -*- C++ -*- |
---|
2 | |
---|
3 | /* |
---|
4 | Heuristics: |
---|
5 | 2 phase |
---|
6 | gap |
---|
7 | list 'level_list' on the nodes on level i implemented by hand |
---|
8 | stack 'active' on the active nodes on level i |
---|
9 | runs heuristic 'highest label' for H1*n relabels |
---|
10 | runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label' |
---|
11 | |
---|
12 | Parameters H0 and H1 are initialized to 20 and 1. |
---|
13 | |
---|
14 | Constructors: |
---|
15 | |
---|
16 | Preflow(Graph, Node, Node, CapMap, FlowMap, bool) : bool must be false if |
---|
17 | FlowMap is not constant zero, and should be true if it is |
---|
18 | |
---|
19 | Members: |
---|
20 | |
---|
21 | void run() |
---|
22 | |
---|
23 | Num flowValue() : returns the value of a maximum flow |
---|
24 | |
---|
25 | void minMinCut(CutMap& M) : sets M to the characteristic vector of the |
---|
26 | minimum min cut. M should be a map of bools initialized to false. ??Is it OK? |
---|
27 | |
---|
28 | void maxMinCut(CutMap& M) : sets M to the characteristic vector of the |
---|
29 | maximum min cut. M should be a map of bools initialized to false. |
---|
30 | |
---|
31 | void minCut(CutMap& M) : sets M to the characteristic vector of |
---|
32 | a min cut. M should be a map of bools initialized to false. |
---|
33 | |
---|
34 | */ |
---|
35 | |
---|
36 | #ifndef HUGO_PREFLOW_H |
---|
37 | #define HUGO_PREFLOW_H |
---|
38 | |
---|
39 | #define H0 20 |
---|
40 | #define H1 1 |
---|
41 | |
---|
42 | #include <vector> |
---|
43 | #include <queue> |
---|
44 | #include <stack> |
---|
45 | |
---|
46 | namespace hugo { |
---|
47 | |
---|
48 | template <typename Graph, typename Num, |
---|
49 | typename CapMap=typename Graph::template EdgeMap<Num>, |
---|
50 | typename FlowMap=typename Graph::template EdgeMap<Num> > |
---|
51 | class Preflow { |
---|
52 | |
---|
53 | typedef typename Graph::Node Node; |
---|
54 | typedef typename Graph::NodeIt NodeIt; |
---|
55 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
56 | typedef typename Graph::InEdgeIt InEdgeIt; |
---|
57 | |
---|
58 | typedef typename std::vector<std::stack<Node> > VecStack; |
---|
59 | typedef typename Graph::template NodeMap<Node> NNMap; |
---|
60 | typedef typename std::vector<Node> VecNode; |
---|
61 | |
---|
62 | const Graph* g; |
---|
63 | Node s; |
---|
64 | Node t; |
---|
65 | const CapMap* capacity; |
---|
66 | FlowMap* flow; |
---|
67 | int n; //the number of nodes of G |
---|
68 | typename Graph::template NodeMap<int> level; |
---|
69 | typename Graph::template NodeMap<Num> excess; |
---|
70 | |
---|
71 | |
---|
72 | public: |
---|
73 | |
---|
74 | enum flowEnum{ |
---|
75 | ZERO_FLOW=0, |
---|
76 | GEN_FLOW=1, |
---|
77 | PREFLOW=2 |
---|
78 | }; |
---|
79 | |
---|
80 | Preflow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity, |
---|
81 | FlowMap& _flow) : |
---|
82 | g(&_G), s(_s), t(_t), capacity(&_capacity), |
---|
83 | flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0) {} |
---|
84 | |
---|
85 | void run() { |
---|
86 | preflow( ZERO_FLOW ); |
---|
87 | } |
---|
88 | |
---|
89 | void preflow( flowEnum fe ) { |
---|
90 | preflowPhase0(fe); |
---|
91 | preflowPhase1(); |
---|
92 | } |
---|
93 | |
---|
94 | void preflowPhase0( flowEnum fe ) { |
---|
95 | |
---|
96 | int heur0=(int)(H0*n); //time while running 'bound decrease' |
---|
97 | int heur1=(int)(H1*n); //time while running 'highest label' |
---|
98 | int heur=heur1; //starting time interval (#of relabels) |
---|
99 | int numrelabel=0; |
---|
100 | |
---|
101 | bool what_heur=1; |
---|
102 | //It is 0 in case 'bound decrease' and 1 in case 'highest label' |
---|
103 | |
---|
104 | bool end=false; |
---|
105 | //Needed for 'bound decrease', true means no active nodes are above bound b. |
---|
106 | |
---|
107 | int k=n-2; //bound on the highest level under n containing a node |
---|
108 | int b=k; //bound on the highest level under n of an active node |
---|
109 | |
---|
110 | VecStack active(n); |
---|
111 | |
---|
112 | NNMap left(*g, INVALID); |
---|
113 | NNMap right(*g, INVALID); |
---|
114 | VecNode level_list(n,INVALID); |
---|
115 | //List of the nodes in level i<n, set to n. |
---|
116 | |
---|
117 | NodeIt v; |
---|
118 | for(g->first(v); g->valid(v); g->next(v)) level.set(v,n); |
---|
119 | //setting each node to level n |
---|
120 | |
---|
121 | switch ( fe ) { |
---|
122 | case PREFLOW: |
---|
123 | { |
---|
124 | //counting the excess |
---|
125 | NodeIt v; |
---|
126 | for(g->first(v); g->valid(v); g->next(v)) { |
---|
127 | Num exc=0; |
---|
128 | |
---|
129 | InEdgeIt e; |
---|
130 | for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e]; |
---|
131 | OutEdgeIt f; |
---|
132 | for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f]; |
---|
133 | |
---|
134 | excess.set(v,exc); |
---|
135 | |
---|
136 | //putting the active nodes into the stack |
---|
137 | int lev=level[v]; |
---|
138 | if ( exc > 0 && lev < n && v != t ) active[lev].push(v); |
---|
139 | } |
---|
140 | break; |
---|
141 | } |
---|
142 | case GEN_FLOW: |
---|
143 | { |
---|
144 | //Counting the excess of t |
---|
145 | Num exc=0; |
---|
146 | |
---|
147 | InEdgeIt e; |
---|
148 | for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e]; |
---|
149 | OutEdgeIt f; |
---|
150 | for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f]; |
---|
151 | |
---|
152 | excess.set(t,exc); |
---|
153 | |
---|
154 | break; |
---|
155 | } |
---|
156 | default: |
---|
157 | break; |
---|
158 | } |
---|
159 | |
---|
160 | preflowPreproc( fe, active, level_list, left, right ); |
---|
161 | //End of preprocessing |
---|
162 | |
---|
163 | |
---|
164 | //Push/relabel on the highest level active nodes. |
---|
165 | while ( true ) { |
---|
166 | if ( b == 0 ) { |
---|
167 | if ( !what_heur && !end && k > 0 ) { |
---|
168 | b=k; |
---|
169 | end=true; |
---|
170 | } else break; |
---|
171 | } |
---|
172 | |
---|
173 | if ( active[b].empty() ) --b; |
---|
174 | else { |
---|
175 | end=false; |
---|
176 | Node w=active[b].top(); |
---|
177 | active[b].pop(); |
---|
178 | int newlevel=push(w,active); |
---|
179 | if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list, |
---|
180 | left, right, b, k, what_heur); |
---|
181 | |
---|
182 | ++numrelabel; |
---|
183 | if ( numrelabel >= heur ) { |
---|
184 | numrelabel=0; |
---|
185 | if ( what_heur ) { |
---|
186 | what_heur=0; |
---|
187 | heur=heur0; |
---|
188 | end=false; |
---|
189 | } else { |
---|
190 | what_heur=1; |
---|
191 | heur=heur1; |
---|
192 | b=k; |
---|
193 | } |
---|
194 | } |
---|
195 | } |
---|
196 | } |
---|
197 | } |
---|
198 | |
---|
199 | |
---|
200 | void preflowPhase1() { |
---|
201 | |
---|
202 | int k=n-2; //bound on the highest level under n containing a node |
---|
203 | int b=k; //bound on the highest level under n of an active node |
---|
204 | |
---|
205 | VecStack active(n); |
---|
206 | level.set(s,0); |
---|
207 | std::queue<Node> bfs_queue; |
---|
208 | bfs_queue.push(s); |
---|
209 | |
---|
210 | while (!bfs_queue.empty()) { |
---|
211 | |
---|
212 | Node v=bfs_queue.front(); |
---|
213 | bfs_queue.pop(); |
---|
214 | int l=level[v]+1; |
---|
215 | |
---|
216 | InEdgeIt e; |
---|
217 | for(g->first(e,v); g->valid(e); g->next(e)) { |
---|
218 | if ( (*capacity)[e] <= (*flow)[e] ) continue; |
---|
219 | Node u=g->tail(e); |
---|
220 | if ( level[u] >= n ) { |
---|
221 | bfs_queue.push(u); |
---|
222 | level.set(u, l); |
---|
223 | if ( excess[u] > 0 ) active[l].push(u); |
---|
224 | } |
---|
225 | } |
---|
226 | |
---|
227 | OutEdgeIt f; |
---|
228 | for(g->first(f,v); g->valid(f); g->next(f)) { |
---|
229 | if ( 0 >= (*flow)[f] ) continue; |
---|
230 | Node u=g->head(f); |
---|
231 | if ( level[u] >= n ) { |
---|
232 | bfs_queue.push(u); |
---|
233 | level.set(u, l); |
---|
234 | if ( excess[u] > 0 ) active[l].push(u); |
---|
235 | } |
---|
236 | } |
---|
237 | } |
---|
238 | b=n-2; |
---|
239 | |
---|
240 | while ( true ) { |
---|
241 | |
---|
242 | if ( b == 0 ) break; |
---|
243 | |
---|
244 | if ( active[b].empty() ) --b; |
---|
245 | else { |
---|
246 | Node w=active[b].top(); |
---|
247 | active[b].pop(); |
---|
248 | int newlevel=push(w,active); |
---|
249 | |
---|
250 | //relabel |
---|
251 | if ( excess[w] > 0 ) { |
---|
252 | level.set(w,++newlevel); |
---|
253 | active[newlevel].push(w); |
---|
254 | b=newlevel; |
---|
255 | } |
---|
256 | } // if stack[b] is nonempty |
---|
257 | } // while(true) |
---|
258 | } |
---|
259 | |
---|
260 | |
---|
261 | //Returns the maximum value of a flow. |
---|
262 | Num flowValue() { |
---|
263 | return excess[t]; |
---|
264 | } |
---|
265 | |
---|
266 | //should be used only between preflowPhase0 and preflowPhase1 |
---|
267 | template<typename _CutMap> |
---|
268 | void actMinCut(_CutMap& M) { |
---|
269 | NodeIt v; |
---|
270 | for(g->first(v); g->valid(v); g->next(v)) |
---|
271 | if ( level[v] < n ) { |
---|
272 | M.set(v,false); |
---|
273 | } else { |
---|
274 | M.set(v,true); |
---|
275 | } |
---|
276 | } |
---|
277 | |
---|
278 | |
---|
279 | |
---|
280 | /* |
---|
281 | Returns the minimum min cut, by a bfs from s in the residual graph. |
---|
282 | */ |
---|
283 | template<typename _CutMap> |
---|
284 | void minMinCut(_CutMap& M) { |
---|
285 | |
---|
286 | std::queue<Node> queue; |
---|
287 | |
---|
288 | M.set(s,true); |
---|
289 | queue.push(s); |
---|
290 | |
---|
291 | while (!queue.empty()) { |
---|
292 | Node w=queue.front(); |
---|
293 | queue.pop(); |
---|
294 | |
---|
295 | OutEdgeIt e; |
---|
296 | for(g->first(e,w) ; g->valid(e); g->next(e)) { |
---|
297 | Node v=g->head(e); |
---|
298 | if (!M[v] && (*flow)[e] < (*capacity)[e] ) { |
---|
299 | queue.push(v); |
---|
300 | M.set(v, true); |
---|
301 | } |
---|
302 | } |
---|
303 | |
---|
304 | InEdgeIt f; |
---|
305 | for(g->first(f,w) ; g->valid(f); g->next(f)) { |
---|
306 | Node v=g->tail(f); |
---|
307 | if (!M[v] && (*flow)[f] > 0 ) { |
---|
308 | queue.push(v); |
---|
309 | M.set(v, true); |
---|
310 | } |
---|
311 | } |
---|
312 | } |
---|
313 | } |
---|
314 | |
---|
315 | |
---|
316 | |
---|
317 | /* |
---|
318 | Returns the maximum min cut, by a reverse bfs |
---|
319 | from t in the residual graph. |
---|
320 | */ |
---|
321 | |
---|
322 | template<typename _CutMap> |
---|
323 | void maxMinCut(_CutMap& M) { |
---|
324 | |
---|
325 | NodeIt v; |
---|
326 | for(g->first(v) ; g->valid(v); g->next(v)) { |
---|
327 | M.set(v, true); |
---|
328 | } |
---|
329 | |
---|
330 | std::queue<Node> queue; |
---|
331 | |
---|
332 | M.set(t,false); |
---|
333 | queue.push(t); |
---|
334 | |
---|
335 | while (!queue.empty()) { |
---|
336 | Node w=queue.front(); |
---|
337 | queue.pop(); |
---|
338 | |
---|
339 | |
---|
340 | InEdgeIt e; |
---|
341 | for(g->first(e,w) ; g->valid(e); g->next(e)) { |
---|
342 | Node v=g->tail(e); |
---|
343 | if (M[v] && (*flow)[e] < (*capacity)[e] ) { |
---|
344 | queue.push(v); |
---|
345 | M.set(v, false); |
---|
346 | } |
---|
347 | } |
---|
348 | |
---|
349 | OutEdgeIt f; |
---|
350 | for(g->first(f,w) ; g->valid(f); g->next(f)) { |
---|
351 | Node v=g->head(f); |
---|
352 | if (M[v] && (*flow)[f] > 0 ) { |
---|
353 | queue.push(v); |
---|
354 | M.set(v, false); |
---|
355 | } |
---|
356 | } |
---|
357 | } |
---|
358 | } |
---|
359 | |
---|
360 | |
---|
361 | template<typename CutMap> |
---|
362 | void minCut(CutMap& M) { |
---|
363 | minMinCut(M); |
---|
364 | } |
---|
365 | |
---|
366 | void resetTarget(Node _t) {t=_t;} |
---|
367 | void resetSource(Node _s) {s=_s;} |
---|
368 | |
---|
369 | void resetCap(const CapMap& _cap) { |
---|
370 | capacity=&_cap; |
---|
371 | } |
---|
372 | |
---|
373 | void resetFlow(FlowMap& _flow) { |
---|
374 | flow=&_flow; |
---|
375 | } |
---|
376 | |
---|
377 | |
---|
378 | private: |
---|
379 | |
---|
380 | int push(Node w, VecStack& active) { |
---|
381 | |
---|
382 | int lev=level[w]; |
---|
383 | Num exc=excess[w]; |
---|
384 | int newlevel=n; //bound on the next level of w |
---|
385 | |
---|
386 | OutEdgeIt e; |
---|
387 | for(g->first(e,w); g->valid(e); g->next(e)) { |
---|
388 | |
---|
389 | if ( (*flow)[e] >= (*capacity)[e] ) continue; |
---|
390 | Node v=g->head(e); |
---|
391 | |
---|
392 | if( lev > level[v] ) { //Push is allowed now |
---|
393 | |
---|
394 | if ( excess[v]<=0 && v!=t && v!=s ) { |
---|
395 | int lev_v=level[v]; |
---|
396 | active[lev_v].push(v); |
---|
397 | } |
---|
398 | |
---|
399 | Num cap=(*capacity)[e]; |
---|
400 | Num flo=(*flow)[e]; |
---|
401 | Num remcap=cap-flo; |
---|
402 | |
---|
403 | if ( remcap >= exc ) { //A nonsaturating push. |
---|
404 | |
---|
405 | flow->set(e, flo+exc); |
---|
406 | excess.set(v, excess[v]+exc); |
---|
407 | exc=0; |
---|
408 | break; |
---|
409 | |
---|
410 | } else { //A saturating push. |
---|
411 | flow->set(e, cap); |
---|
412 | excess.set(v, excess[v]+remcap); |
---|
413 | exc-=remcap; |
---|
414 | } |
---|
415 | } else if ( newlevel > level[v] ) newlevel = level[v]; |
---|
416 | } //for out edges wv |
---|
417 | |
---|
418 | if ( exc > 0 ) { |
---|
419 | InEdgeIt e; |
---|
420 | for(g->first(e,w); g->valid(e); g->next(e)) { |
---|
421 | |
---|
422 | if( (*flow)[e] <= 0 ) continue; |
---|
423 | Node v=g->tail(e); |
---|
424 | |
---|
425 | if( lev > level[v] ) { //Push is allowed now |
---|
426 | |
---|
427 | if ( excess[v]<=0 && v!=t && v!=s ) { |
---|
428 | int lev_v=level[v]; |
---|
429 | active[lev_v].push(v); |
---|
430 | } |
---|
431 | |
---|
432 | Num flo=(*flow)[e]; |
---|
433 | |
---|
434 | if ( flo >= exc ) { //A nonsaturating push. |
---|
435 | |
---|
436 | flow->set(e, flo-exc); |
---|
437 | excess.set(v, excess[v]+exc); |
---|
438 | exc=0; |
---|
439 | break; |
---|
440 | } else { //A saturating push. |
---|
441 | |
---|
442 | excess.set(v, excess[v]+flo); |
---|
443 | exc-=flo; |
---|
444 | flow->set(e,0); |
---|
445 | } |
---|
446 | } else if ( newlevel > level[v] ) newlevel = level[v]; |
---|
447 | } //for in edges vw |
---|
448 | |
---|
449 | } // if w still has excess after the out edge for cycle |
---|
450 | |
---|
451 | excess.set(w, exc); |
---|
452 | |
---|
453 | return newlevel; |
---|
454 | } |
---|
455 | |
---|
456 | |
---|
457 | void preflowPreproc ( flowEnum fe, VecStack& active, |
---|
458 | VecNode& level_list, NNMap& left, NNMap& right ) { |
---|
459 | |
---|
460 | std::queue<Node> bfs_queue; |
---|
461 | |
---|
462 | switch ( fe ) { |
---|
463 | case ZERO_FLOW: |
---|
464 | { |
---|
465 | //Reverse_bfs from t, to find the starting level. |
---|
466 | level.set(t,0); |
---|
467 | bfs_queue.push(t); |
---|
468 | |
---|
469 | while (!bfs_queue.empty()) { |
---|
470 | |
---|
471 | Node v=bfs_queue.front(); |
---|
472 | bfs_queue.pop(); |
---|
473 | int l=level[v]+1; |
---|
474 | |
---|
475 | InEdgeIt e; |
---|
476 | for(g->first(e,v); g->valid(e); g->next(e)) { |
---|
477 | Node w=g->tail(e); |
---|
478 | if ( level[w] == n && w != s ) { |
---|
479 | bfs_queue.push(w); |
---|
480 | Node first=level_list[l]; |
---|
481 | if ( g->valid(first) ) left.set(first,w); |
---|
482 | right.set(w,first); |
---|
483 | level_list[l]=w; |
---|
484 | level.set(w, l); |
---|
485 | } |
---|
486 | } |
---|
487 | } |
---|
488 | |
---|
489 | //the starting flow |
---|
490 | OutEdgeIt e; |
---|
491 | for(g->first(e,s); g->valid(e); g->next(e)) |
---|
492 | { |
---|
493 | Num c=(*capacity)[e]; |
---|
494 | if ( c <= 0 ) continue; |
---|
495 | Node w=g->head(e); |
---|
496 | if ( level[w] < n ) { |
---|
497 | if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w); |
---|
498 | flow->set(e, c); |
---|
499 | excess.set(w, excess[w]+c); |
---|
500 | } |
---|
501 | } |
---|
502 | break; |
---|
503 | } |
---|
504 | |
---|
505 | case GEN_FLOW: |
---|
506 | case PREFLOW: |
---|
507 | { |
---|
508 | //Reverse_bfs from t in the residual graph, |
---|
509 | //to find the starting level. |
---|
510 | level.set(t,0); |
---|
511 | bfs_queue.push(t); |
---|
512 | |
---|
513 | while (!bfs_queue.empty()) { |
---|
514 | |
---|
515 | Node v=bfs_queue.front(); |
---|
516 | bfs_queue.pop(); |
---|
517 | int l=level[v]+1; |
---|
518 | |
---|
519 | InEdgeIt e; |
---|
520 | for(g->first(e,v); g->valid(e); g->next(e)) { |
---|
521 | if ( (*capacity)[e] <= (*flow)[e] ) continue; |
---|
522 | Node w=g->tail(e); |
---|
523 | if ( level[w] == n && w != s ) { |
---|
524 | bfs_queue.push(w); |
---|
525 | Node first=level_list[l]; |
---|
526 | if ( g->valid(first) ) left.set(first,w); |
---|
527 | right.set(w,first); |
---|
528 | level_list[l]=w; |
---|
529 | level.set(w, l); |
---|
530 | } |
---|
531 | } |
---|
532 | |
---|
533 | OutEdgeIt f; |
---|
534 | for(g->first(f,v); g->valid(f); g->next(f)) { |
---|
535 | if ( 0 >= (*flow)[f] ) continue; |
---|
536 | Node w=g->head(f); |
---|
537 | if ( level[w] == n && w != s ) { |
---|
538 | bfs_queue.push(w); |
---|
539 | Node first=level_list[l]; |
---|
540 | if ( g->valid(first) ) left.set(first,w); |
---|
541 | right.set(w,first); |
---|
542 | level_list[l]=w; |
---|
543 | level.set(w, l); |
---|
544 | } |
---|
545 | } |
---|
546 | } |
---|
547 | |
---|
548 | |
---|
549 | //the starting flow |
---|
550 | OutEdgeIt e; |
---|
551 | for(g->first(e,s); g->valid(e); g->next(e)) |
---|
552 | { |
---|
553 | Num rem=(*capacity)[e]-(*flow)[e]; |
---|
554 | if ( rem <= 0 ) continue; |
---|
555 | Node w=g->head(e); |
---|
556 | if ( level[w] < n ) { |
---|
557 | if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w); |
---|
558 | flow->set(e, (*capacity)[e]); |
---|
559 | excess.set(w, excess[w]+rem); |
---|
560 | } |
---|
561 | } |
---|
562 | |
---|
563 | InEdgeIt f; |
---|
564 | for(g->first(f,s); g->valid(f); g->next(f)) |
---|
565 | { |
---|
566 | if ( (*flow)[f] <= 0 ) continue; |
---|
567 | Node w=g->tail(f); |
---|
568 | if ( level[w] < n ) { |
---|
569 | if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w); |
---|
570 | excess.set(w, excess[w]+(*flow)[f]); |
---|
571 | flow->set(f, 0); |
---|
572 | } |
---|
573 | } |
---|
574 | break; |
---|
575 | } //case PREFLOW |
---|
576 | } |
---|
577 | } //preflowPreproc |
---|
578 | |
---|
579 | |
---|
580 | |
---|
581 | void relabel(Node w, int newlevel, VecStack& active, |
---|
582 | VecNode& level_list, NNMap& left, |
---|
583 | NNMap& right, int& b, int& k, bool what_heur ) { |
---|
584 | |
---|
585 | Num lev=level[w]; |
---|
586 | |
---|
587 | Node right_n=right[w]; |
---|
588 | Node left_n=left[w]; |
---|
589 | |
---|
590 | //unlacing starts |
---|
591 | if ( g->valid(right_n) ) { |
---|
592 | if ( g->valid(left_n) ) { |
---|
593 | right.set(left_n, right_n); |
---|
594 | left.set(right_n, left_n); |
---|
595 | } else { |
---|
596 | level_list[lev]=right_n; |
---|
597 | left.set(right_n, INVALID); |
---|
598 | } |
---|
599 | } else { |
---|
600 | if ( g->valid(left_n) ) { |
---|
601 | right.set(left_n, INVALID); |
---|
602 | } else { |
---|
603 | level_list[lev]=INVALID; |
---|
604 | } |
---|
605 | } |
---|
606 | //unlacing ends |
---|
607 | |
---|
608 | if ( !g->valid(level_list[lev]) ) { |
---|
609 | |
---|
610 | //gapping starts |
---|
611 | for (int i=lev; i!=k ; ) { |
---|
612 | Node v=level_list[++i]; |
---|
613 | while ( g->valid(v) ) { |
---|
614 | level.set(v,n); |
---|
615 | v=right[v]; |
---|
616 | } |
---|
617 | level_list[i]=INVALID; |
---|
618 | if ( !what_heur ) { |
---|
619 | while ( !active[i].empty() ) { |
---|
620 | active[i].pop(); //FIXME: ezt szebben kene |
---|
621 | } |
---|
622 | } |
---|
623 | } |
---|
624 | |
---|
625 | level.set(w,n); |
---|
626 | b=lev-1; |
---|
627 | k=b; |
---|
628 | //gapping ends |
---|
629 | |
---|
630 | } else { |
---|
631 | |
---|
632 | if ( newlevel == n ) level.set(w,n); |
---|
633 | else { |
---|
634 | level.set(w,++newlevel); |
---|
635 | active[newlevel].push(w); |
---|
636 | if ( what_heur ) b=newlevel; |
---|
637 | if ( k < newlevel ) ++k; //now k=newlevel |
---|
638 | Node first=level_list[newlevel]; |
---|
639 | if ( g->valid(first) ) left.set(first,w); |
---|
640 | right.set(w,first); |
---|
641 | left.set(w,INVALID); |
---|
642 | level_list[newlevel]=w; |
---|
643 | } |
---|
644 | } |
---|
645 | |
---|
646 | } //relabel |
---|
647 | |
---|
648 | |
---|
649 | }; |
---|
650 | |
---|
651 | } //namespace hugo |
---|
652 | |
---|
653 | #endif //HUGO_PREFLOW_H |
---|
654 | |
---|
655 | |
---|
656 | |
---|
657 | |
---|