[478] | 1 | // -*- C++ -*- |
---|
| 2 | |
---|
| 3 | /* |
---|
[485] | 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' |
---|
[478] | 11 | |
---|
[485] | 12 | Parameters H0 and H1 are initialized to 20 and 1. |
---|
[478] | 13 | |
---|
[485] | 14 | Constructors: |
---|
[478] | 15 | |
---|
[485] | 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 |
---|
[478] | 18 | |
---|
[485] | 19 | Members: |
---|
[478] | 20 | |
---|
[485] | 21 | void run() |
---|
[478] | 22 | |
---|
[485] | 23 | Num flowValue() : returns the value of a maximum flow |
---|
[478] | 24 | |
---|
[485] | 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? |
---|
[478] | 27 | |
---|
[485] | 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. |
---|
[478] | 30 | |
---|
[485] | 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. |
---|
[478] | 33 | |
---|
| 34 | */ |
---|
| 35 | |
---|
[480] | 36 | #ifndef HUGO_MAX_FLOW_H |
---|
| 37 | #define HUGO_MAX_FLOW_H |
---|
[478] | 38 | |
---|
| 39 | #define H0 20 |
---|
| 40 | #define H1 1 |
---|
| 41 | |
---|
| 42 | #include <vector> |
---|
| 43 | #include <queue> |
---|
| 44 | #include <stack> |
---|
| 45 | |
---|
| 46 | #include <graph_wrapper.h> |
---|
| 47 | #include <bfs_iterator.h> |
---|
| 48 | #include <invalid.h> |
---|
| 49 | #include <maps.h> |
---|
| 50 | #include <for_each_macros.h> |
---|
| 51 | |
---|
| 52 | |
---|
| 53 | namespace hugo { |
---|
| 54 | |
---|
[485] | 55 | ///\author Marton Makai, Jacint Szabo |
---|
[478] | 56 | template <typename Graph, typename Num, |
---|
| 57 | typename CapMap=typename Graph::template EdgeMap<Num>, |
---|
| 58 | typename FlowMap=typename Graph::template EdgeMap<Num> > |
---|
| 59 | class MaxFlow { |
---|
| 60 | |
---|
| 61 | typedef typename Graph::Node Node; |
---|
| 62 | typedef typename Graph::NodeIt NodeIt; |
---|
| 63 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 64 | typedef typename Graph::InEdgeIt InEdgeIt; |
---|
| 65 | |
---|
| 66 | typedef typename std::vector<std::stack<Node> > VecStack; |
---|
| 67 | typedef typename Graph::template NodeMap<Node> NNMap; |
---|
| 68 | typedef typename std::vector<Node> VecNode; |
---|
| 69 | |
---|
| 70 | const Graph* g; |
---|
| 71 | Node s; |
---|
| 72 | Node t; |
---|
| 73 | const CapMap* capacity; |
---|
| 74 | FlowMap* flow; |
---|
| 75 | int n; //the number of nodes of G |
---|
| 76 | typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW; |
---|
| 77 | typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt; |
---|
| 78 | typedef typename ResGW::Edge ResGWEdge; |
---|
| 79 | //typedef typename ResGW::template NodeMap<bool> ReachedMap; |
---|
| 80 | typedef typename Graph::template NodeMap<int> ReachedMap; |
---|
| 81 | ReachedMap level; |
---|
| 82 | //level works as a bool map in augmenting path algorithms |
---|
| 83 | //and is used by bfs for storing reached information. |
---|
| 84 | //In preflow, it shows levels of nodes. |
---|
| 85 | //typename Graph::template NodeMap<int> level; |
---|
| 86 | typename Graph::template NodeMap<Num> excess; |
---|
| 87 | |
---|
| 88 | public: |
---|
| 89 | |
---|
| 90 | enum flowEnum{ |
---|
| 91 | ZERO_FLOW=0, |
---|
| 92 | GEN_FLOW=1, |
---|
| 93 | PREFLOW=2 |
---|
| 94 | }; |
---|
| 95 | |
---|
| 96 | MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity, |
---|
| 97 | FlowMap& _flow) : |
---|
| 98 | g(&_G), s(_s), t(_t), capacity(&_capacity), |
---|
| 99 | flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0) {} |
---|
| 100 | |
---|
[485] | 101 | /// A max flow algorithm is run. |
---|
| 102 | ///\pre the flow have to be 0 at the beginning. |
---|
[478] | 103 | void run() { |
---|
| 104 | preflow( ZERO_FLOW ); |
---|
| 105 | } |
---|
| 106 | |
---|
[485] | 107 | /// A preflow algorithm is run. The initial edge-set have to be a flow, |
---|
| 108 | /// or from a preflow, according to \c fe. |
---|
[478] | 109 | void preflow( flowEnum fe ) { |
---|
| 110 | preflowPhase0(fe); |
---|
| 111 | preflowPhase1(); |
---|
| 112 | } |
---|
| 113 | |
---|
[485] | 114 | /// Run the first phase of preflow, starting from a 0 flow, from a flow, |
---|
| 115 | /// or from a preflow, according to \c fe. |
---|
[478] | 116 | void preflowPhase0( flowEnum fe ); |
---|
| 117 | |
---|
[485] | 118 | /// Second phase of preflow. |
---|
[478] | 119 | void preflowPhase1(); |
---|
| 120 | |
---|
[485] | 121 | /// Starting from a flow, this method searches for an augmenting path |
---|
| 122 | /// according to the Edmonds-Karp algorithm |
---|
| 123 | /// and augments the flow on if any. |
---|
[478] | 124 | bool augmentOnShortestPath(); |
---|
| 125 | |
---|
[485] | 126 | /// Starting from a flow, this method searches for an augmenting blockin |
---|
| 127 | /// flow according to Dinits' algorithm and augments the flow on if any. |
---|
| 128 | /// The blocking flow is computed in a physically constructed |
---|
| 129 | /// residual graph of type \c Mutablegraph. |
---|
[478] | 130 | template<typename MutableGraph> bool augmentOnBlockingFlow(); |
---|
| 131 | |
---|
[485] | 132 | /// The same as \c augmentOnBlockingFlow<MutableGraph> but the |
---|
| 133 | /// residual graph is not constructed physically. |
---|
[478] | 134 | bool augmentOnBlockingFlow2(); |
---|
| 135 | |
---|
| 136 | /// Returns the actual flow value. |
---|
| 137 | /// More precisely, it returns the negative excess of s, thus |
---|
| 138 | /// this works also for preflows. |
---|
| 139 | Num flowValue() { |
---|
| 140 | Num a=0; |
---|
| 141 | FOR_EACH_INC_LOC(OutEdgeIt, e, *g, s) a+=(*flow)[e]; |
---|
| 142 | FOR_EACH_INC_LOC(InEdgeIt, e, *g, s) a-=(*flow)[e]; |
---|
| 143 | return a; |
---|
| 144 | } |
---|
| 145 | |
---|
[485] | 146 | /// Should be used between preflowPhase0 and preflowPhase1. |
---|
| 147 | ///\todo We have to make some status variable which shows the actual state |
---|
| 148 | /// of the class. This enables us to determine which methods are valid |
---|
| 149 | /// for MinCut computation |
---|
[478] | 150 | template<typename _CutMap> |
---|
| 151 | void actMinCut(_CutMap& M) { |
---|
| 152 | NodeIt v; |
---|
[485] | 153 | for(g->first(v); g->valid(v); g->next(v)) { |
---|
| 154 | if ( level[v] < n ) { |
---|
| 155 | M.set(v,false); |
---|
| 156 | } else { |
---|
| 157 | M.set(v,true); |
---|
| 158 | } |
---|
[478] | 159 | } |
---|
| 160 | } |
---|
| 161 | |
---|
| 162 | |
---|
[485] | 163 | /// The unique inclusionwise minimum cut is computed by |
---|
| 164 | /// processing a bfs from s in the residual graph. |
---|
| 165 | ///\pre flow have to be a max flow otherwise it will the whole node-set. |
---|
[478] | 166 | template<typename _CutMap> |
---|
| 167 | void minMinCut(_CutMap& M) { |
---|
| 168 | |
---|
| 169 | std::queue<Node> queue; |
---|
| 170 | |
---|
| 171 | M.set(s,true); |
---|
| 172 | queue.push(s); |
---|
| 173 | |
---|
| 174 | while (!queue.empty()) { |
---|
| 175 | Node w=queue.front(); |
---|
| 176 | queue.pop(); |
---|
| 177 | |
---|
| 178 | OutEdgeIt e; |
---|
| 179 | for(g->first(e,w) ; g->valid(e); g->next(e)) { |
---|
| 180 | Node v=g->head(e); |
---|
| 181 | if (!M[v] && (*flow)[e] < (*capacity)[e] ) { |
---|
| 182 | queue.push(v); |
---|
| 183 | M.set(v, true); |
---|
| 184 | } |
---|
| 185 | } |
---|
| 186 | |
---|
| 187 | InEdgeIt f; |
---|
| 188 | for(g->first(f,w) ; g->valid(f); g->next(f)) { |
---|
| 189 | Node v=g->tail(f); |
---|
| 190 | if (!M[v] && (*flow)[f] > 0 ) { |
---|
| 191 | queue.push(v); |
---|
| 192 | M.set(v, true); |
---|
| 193 | } |
---|
| 194 | } |
---|
| 195 | } |
---|
| 196 | } |
---|
| 197 | |
---|
| 198 | |
---|
[485] | 199 | /// The unique inclusionwise maximum cut is computed by |
---|
| 200 | /// processing a reverse bfs from t in the residual graph. |
---|
| 201 | ///\pre flow have to be a max flow otherwise it will be empty. |
---|
[478] | 202 | template<typename _CutMap> |
---|
| 203 | void maxMinCut(_CutMap& M) { |
---|
| 204 | |
---|
| 205 | NodeIt v; |
---|
| 206 | for(g->first(v) ; g->valid(v); g->next(v)) { |
---|
| 207 | M.set(v, true); |
---|
| 208 | } |
---|
| 209 | |
---|
| 210 | std::queue<Node> queue; |
---|
| 211 | |
---|
| 212 | M.set(t,false); |
---|
| 213 | queue.push(t); |
---|
| 214 | |
---|
| 215 | while (!queue.empty()) { |
---|
| 216 | Node w=queue.front(); |
---|
| 217 | queue.pop(); |
---|
| 218 | |
---|
| 219 | |
---|
| 220 | InEdgeIt e; |
---|
| 221 | for(g->first(e,w) ; g->valid(e); g->next(e)) { |
---|
| 222 | Node v=g->tail(e); |
---|
| 223 | if (M[v] && (*flow)[e] < (*capacity)[e] ) { |
---|
| 224 | queue.push(v); |
---|
| 225 | M.set(v, false); |
---|
| 226 | } |
---|
| 227 | } |
---|
| 228 | |
---|
| 229 | OutEdgeIt f; |
---|
| 230 | for(g->first(f,w) ; g->valid(f); g->next(f)) { |
---|
| 231 | Node v=g->head(f); |
---|
| 232 | if (M[v] && (*flow)[f] > 0 ) { |
---|
| 233 | queue.push(v); |
---|
| 234 | M.set(v, false); |
---|
| 235 | } |
---|
| 236 | } |
---|
| 237 | } |
---|
| 238 | } |
---|
| 239 | |
---|
| 240 | |
---|
[485] | 241 | /// A minimum cut is computed. |
---|
[478] | 242 | template<typename CutMap> |
---|
[485] | 243 | void minCut(CutMap& M) { minMinCut(M); } |
---|
[478] | 244 | |
---|
[485] | 245 | /// |
---|
| 246 | void resetSource(Node _s) {s=_s;} |
---|
| 247 | /// |
---|
[478] | 248 | void resetTarget(Node _t) {t=_t;} |
---|
| 249 | |
---|
[485] | 250 | /// capacity-map is changed. |
---|
| 251 | void resetCap(const CapMap& _cap) { capacity=&_cap; } |
---|
[478] | 252 | |
---|
[485] | 253 | /// flow-map is changed. |
---|
| 254 | void resetFlow(FlowMap& _flow) { flow=&_flow; } |
---|
[478] | 255 | |
---|
| 256 | |
---|
| 257 | private: |
---|
| 258 | |
---|
| 259 | int push(Node w, VecStack& active) { |
---|
| 260 | |
---|
| 261 | int lev=level[w]; |
---|
| 262 | Num exc=excess[w]; |
---|
| 263 | int newlevel=n; //bound on the next level of w |
---|
| 264 | |
---|
| 265 | OutEdgeIt e; |
---|
| 266 | for(g->first(e,w); g->valid(e); g->next(e)) { |
---|
| 267 | |
---|
| 268 | if ( (*flow)[e] >= (*capacity)[e] ) continue; |
---|
| 269 | Node v=g->head(e); |
---|
| 270 | |
---|
| 271 | if( lev > level[v] ) { //Push is allowed now |
---|
| 272 | |
---|
| 273 | if ( excess[v]<=0 && v!=t && v!=s ) { |
---|
| 274 | int lev_v=level[v]; |
---|
| 275 | active[lev_v].push(v); |
---|
| 276 | } |
---|
| 277 | |
---|
| 278 | Num cap=(*capacity)[e]; |
---|
| 279 | Num flo=(*flow)[e]; |
---|
| 280 | Num remcap=cap-flo; |
---|
| 281 | |
---|
| 282 | if ( remcap >= exc ) { //A nonsaturating push. |
---|
| 283 | |
---|
| 284 | flow->set(e, flo+exc); |
---|
| 285 | excess.set(v, excess[v]+exc); |
---|
| 286 | exc=0; |
---|
| 287 | break; |
---|
| 288 | |
---|
| 289 | } else { //A saturating push. |
---|
| 290 | flow->set(e, cap); |
---|
| 291 | excess.set(v, excess[v]+remcap); |
---|
| 292 | exc-=remcap; |
---|
| 293 | } |
---|
| 294 | } else if ( newlevel > level[v] ) newlevel = level[v]; |
---|
| 295 | } //for out edges wv |
---|
| 296 | |
---|
| 297 | if ( exc > 0 ) { |
---|
| 298 | InEdgeIt e; |
---|
| 299 | for(g->first(e,w); g->valid(e); g->next(e)) { |
---|
| 300 | |
---|
| 301 | if( (*flow)[e] <= 0 ) continue; |
---|
| 302 | Node v=g->tail(e); |
---|
| 303 | |
---|
| 304 | if( lev > level[v] ) { //Push is allowed now |
---|
| 305 | |
---|
| 306 | if ( excess[v]<=0 && v!=t && v!=s ) { |
---|
| 307 | int lev_v=level[v]; |
---|
| 308 | active[lev_v].push(v); |
---|
| 309 | } |
---|
| 310 | |
---|
| 311 | Num flo=(*flow)[e]; |
---|
| 312 | |
---|
| 313 | if ( flo >= exc ) { //A nonsaturating push. |
---|
| 314 | |
---|
| 315 | flow->set(e, flo-exc); |
---|
| 316 | excess.set(v, excess[v]+exc); |
---|
| 317 | exc=0; |
---|
| 318 | break; |
---|
| 319 | } else { //A saturating push. |
---|
| 320 | |
---|
| 321 | excess.set(v, excess[v]+flo); |
---|
| 322 | exc-=flo; |
---|
| 323 | flow->set(e,0); |
---|
| 324 | } |
---|
| 325 | } else if ( newlevel > level[v] ) newlevel = level[v]; |
---|
| 326 | } //for in edges vw |
---|
| 327 | |
---|
| 328 | } // if w still has excess after the out edge for cycle |
---|
| 329 | |
---|
| 330 | excess.set(w, exc); |
---|
| 331 | |
---|
| 332 | return newlevel; |
---|
[485] | 333 | } |
---|
[478] | 334 | |
---|
| 335 | |
---|
| 336 | void preflowPreproc ( flowEnum fe, VecStack& active, |
---|
| 337 | VecNode& level_list, NNMap& left, NNMap& right ) { |
---|
| 338 | |
---|
[485] | 339 | std::queue<Node> bfs_queue; |
---|
[478] | 340 | |
---|
[485] | 341 | switch ( fe ) { |
---|
| 342 | case ZERO_FLOW: |
---|
| 343 | { |
---|
| 344 | //Reverse_bfs from t, to find the starting level. |
---|
| 345 | level.set(t,0); |
---|
| 346 | bfs_queue.push(t); |
---|
[478] | 347 | |
---|
[485] | 348 | while (!bfs_queue.empty()) { |
---|
[478] | 349 | |
---|
[485] | 350 | Node v=bfs_queue.front(); |
---|
| 351 | bfs_queue.pop(); |
---|
| 352 | int l=level[v]+1; |
---|
[478] | 353 | |
---|
[485] | 354 | InEdgeIt e; |
---|
| 355 | for(g->first(e,v); g->valid(e); g->next(e)) { |
---|
| 356 | Node w=g->tail(e); |
---|
| 357 | if ( level[w] == n && w != s ) { |
---|
| 358 | bfs_queue.push(w); |
---|
| 359 | Node first=level_list[l]; |
---|
| 360 | if ( g->valid(first) ) left.set(first,w); |
---|
| 361 | right.set(w,first); |
---|
| 362 | level_list[l]=w; |
---|
| 363 | level.set(w, l); |
---|
| 364 | } |
---|
| 365 | } |
---|
| 366 | } |
---|
[478] | 367 | |
---|
[485] | 368 | //the starting flow |
---|
| 369 | OutEdgeIt e; |
---|
| 370 | for(g->first(e,s); g->valid(e); g->next(e)) |
---|
| 371 | { |
---|
| 372 | Num c=(*capacity)[e]; |
---|
| 373 | if ( c <= 0 ) continue; |
---|
| 374 | Node w=g->head(e); |
---|
| 375 | if ( level[w] < n ) { |
---|
| 376 | if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w); |
---|
| 377 | flow->set(e, c); |
---|
| 378 | excess.set(w, excess[w]+c); |
---|
| 379 | } |
---|
| 380 | } |
---|
| 381 | break; |
---|
| 382 | } |
---|
[478] | 383 | |
---|
[485] | 384 | case GEN_FLOW: |
---|
| 385 | case PREFLOW: |
---|
| 386 | { |
---|
| 387 | //Reverse_bfs from t in the residual graph, |
---|
| 388 | //to find the starting level. |
---|
| 389 | level.set(t,0); |
---|
| 390 | bfs_queue.push(t); |
---|
[478] | 391 | |
---|
[485] | 392 | while (!bfs_queue.empty()) { |
---|
[478] | 393 | |
---|
[485] | 394 | Node v=bfs_queue.front(); |
---|
| 395 | bfs_queue.pop(); |
---|
| 396 | int l=level[v]+1; |
---|
[478] | 397 | |
---|
[485] | 398 | InEdgeIt e; |
---|
| 399 | for(g->first(e,v); g->valid(e); g->next(e)) { |
---|
| 400 | if ( (*capacity)[e] <= (*flow)[e] ) continue; |
---|
| 401 | Node w=g->tail(e); |
---|
| 402 | if ( level[w] == n && w != s ) { |
---|
| 403 | bfs_queue.push(w); |
---|
| 404 | Node first=level_list[l]; |
---|
| 405 | if ( g->valid(first) ) left.set(first,w); |
---|
| 406 | right.set(w,first); |
---|
| 407 | level_list[l]=w; |
---|
| 408 | level.set(w, l); |
---|
| 409 | } |
---|
| 410 | } |
---|
[478] | 411 | |
---|
[485] | 412 | OutEdgeIt f; |
---|
| 413 | for(g->first(f,v); g->valid(f); g->next(f)) { |
---|
| 414 | if ( 0 >= (*flow)[f] ) continue; |
---|
| 415 | Node w=g->head(f); |
---|
| 416 | if ( level[w] == n && w != s ) { |
---|
| 417 | bfs_queue.push(w); |
---|
| 418 | Node first=level_list[l]; |
---|
| 419 | if ( g->valid(first) ) left.set(first,w); |
---|
| 420 | right.set(w,first); |
---|
| 421 | level_list[l]=w; |
---|
| 422 | level.set(w, l); |
---|
| 423 | } |
---|
| 424 | } |
---|
| 425 | } |
---|
[478] | 426 | |
---|
| 427 | |
---|
[485] | 428 | //the starting flow |
---|
| 429 | OutEdgeIt e; |
---|
| 430 | for(g->first(e,s); g->valid(e); g->next(e)) |
---|
| 431 | { |
---|
| 432 | Num rem=(*capacity)[e]-(*flow)[e]; |
---|
| 433 | if ( rem <= 0 ) continue; |
---|
| 434 | Node w=g->head(e); |
---|
| 435 | if ( level[w] < n ) { |
---|
| 436 | if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w); |
---|
| 437 | flow->set(e, (*capacity)[e]); |
---|
| 438 | excess.set(w, excess[w]+rem); |
---|
| 439 | } |
---|
| 440 | } |
---|
[478] | 441 | |
---|
[485] | 442 | InEdgeIt f; |
---|
| 443 | for(g->first(f,s); g->valid(f); g->next(f)) |
---|
| 444 | { |
---|
| 445 | if ( (*flow)[f] <= 0 ) continue; |
---|
| 446 | Node w=g->tail(f); |
---|
| 447 | if ( level[w] < n ) { |
---|
| 448 | if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w); |
---|
| 449 | excess.set(w, excess[w]+(*flow)[f]); |
---|
| 450 | flow->set(f, 0); |
---|
| 451 | } |
---|
| 452 | } |
---|
| 453 | break; |
---|
| 454 | } //case PREFLOW |
---|
| 455 | } |
---|
| 456 | } //preflowPreproc |
---|
[478] | 457 | |
---|
| 458 | |
---|
| 459 | |
---|
| 460 | void relabel(Node w, int newlevel, VecStack& active, |
---|
| 461 | VecNode& level_list, NNMap& left, |
---|
| 462 | NNMap& right, int& b, int& k, bool what_heur ) |
---|
| 463 | { |
---|
| 464 | |
---|
| 465 | Num lev=level[w]; |
---|
| 466 | |
---|
| 467 | Node right_n=right[w]; |
---|
| 468 | Node left_n=left[w]; |
---|
| 469 | |
---|
| 470 | //unlacing starts |
---|
| 471 | if ( g->valid(right_n) ) { |
---|
| 472 | if ( g->valid(left_n) ) { |
---|
| 473 | right.set(left_n, right_n); |
---|
| 474 | left.set(right_n, left_n); |
---|
| 475 | } else { |
---|
| 476 | level_list[lev]=right_n; |
---|
| 477 | left.set(right_n, INVALID); |
---|
| 478 | } |
---|
| 479 | } else { |
---|
| 480 | if ( g->valid(left_n) ) { |
---|
| 481 | right.set(left_n, INVALID); |
---|
| 482 | } else { |
---|
| 483 | level_list[lev]=INVALID; |
---|
| 484 | } |
---|
| 485 | } |
---|
| 486 | //unlacing ends |
---|
| 487 | |
---|
| 488 | if ( !g->valid(level_list[lev]) ) { |
---|
| 489 | |
---|
| 490 | //gapping starts |
---|
| 491 | for (int i=lev; i!=k ; ) { |
---|
| 492 | Node v=level_list[++i]; |
---|
| 493 | while ( g->valid(v) ) { |
---|
| 494 | level.set(v,n); |
---|
| 495 | v=right[v]; |
---|
| 496 | } |
---|
| 497 | level_list[i]=INVALID; |
---|
| 498 | if ( !what_heur ) { |
---|
| 499 | while ( !active[i].empty() ) { |
---|
| 500 | active[i].pop(); //FIXME: ezt szebben kene |
---|
| 501 | } |
---|
| 502 | } |
---|
| 503 | } |
---|
| 504 | |
---|
| 505 | level.set(w,n); |
---|
| 506 | b=lev-1; |
---|
| 507 | k=b; |
---|
| 508 | //gapping ends |
---|
| 509 | |
---|
| 510 | } else { |
---|
| 511 | |
---|
| 512 | if ( newlevel == n ) level.set(w,n); |
---|
| 513 | else { |
---|
| 514 | level.set(w,++newlevel); |
---|
| 515 | active[newlevel].push(w); |
---|
| 516 | if ( what_heur ) b=newlevel; |
---|
| 517 | if ( k < newlevel ) ++k; //now k=newlevel |
---|
| 518 | Node first=level_list[newlevel]; |
---|
| 519 | if ( g->valid(first) ) left.set(first,w); |
---|
| 520 | right.set(w,first); |
---|
| 521 | left.set(w,INVALID); |
---|
| 522 | level_list[newlevel]=w; |
---|
| 523 | } |
---|
| 524 | } |
---|
| 525 | |
---|
| 526 | } //relabel |
---|
| 527 | |
---|
| 528 | |
---|
| 529 | template<typename MapGraphWrapper> |
---|
| 530 | class DistanceMap { |
---|
| 531 | protected: |
---|
| 532 | const MapGraphWrapper* g; |
---|
| 533 | typename MapGraphWrapper::template NodeMap<int> dist; |
---|
| 534 | public: |
---|
| 535 | DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { } |
---|
| 536 | void set(const typename MapGraphWrapper::Node& n, int a) { |
---|
| 537 | dist.set(n, a); |
---|
| 538 | } |
---|
| 539 | int operator[](const typename MapGraphWrapper::Node& n) |
---|
[485] | 540 | { return dist[n]; } |
---|
| 541 | // int get(const typename MapGraphWrapper::Node& n) const { |
---|
| 542 | // return dist[n]; } |
---|
| 543 | // bool get(const typename MapGraphWrapper::Edge& e) const { |
---|
| 544 | // return (dist.get(g->tail(e))<dist.get(g->head(e))); } |
---|
[478] | 545 | bool operator[](const typename MapGraphWrapper::Edge& e) const { |
---|
| 546 | return (dist[g->tail(e)]<dist[g->head(e)]); |
---|
| 547 | } |
---|
| 548 | }; |
---|
| 549 | |
---|
| 550 | }; |
---|
| 551 | |
---|
| 552 | |
---|
| 553 | template <typename Graph, typename Num, typename CapMap, typename FlowMap> |
---|
| 554 | void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase0( flowEnum fe ) |
---|
| 555 | { |
---|
| 556 | |
---|
[485] | 557 | int heur0=(int)(H0*n); //time while running 'bound decrease' |
---|
| 558 | int heur1=(int)(H1*n); //time while running 'highest label' |
---|
| 559 | int heur=heur1; //starting time interval (#of relabels) |
---|
| 560 | int numrelabel=0; |
---|
[478] | 561 | |
---|
[485] | 562 | bool what_heur=1; |
---|
| 563 | //It is 0 in case 'bound decrease' and 1 in case 'highest label' |
---|
[478] | 564 | |
---|
[485] | 565 | bool end=false; |
---|
| 566 | //Needed for 'bound decrease', true means no active nodes are above bound b. |
---|
[478] | 567 | |
---|
[485] | 568 | int k=n-2; //bound on the highest level under n containing a node |
---|
| 569 | int b=k; //bound on the highest level under n of an active node |
---|
[478] | 570 | |
---|
[485] | 571 | VecStack active(n); |
---|
[478] | 572 | |
---|
[485] | 573 | NNMap left(*g, INVALID); |
---|
| 574 | NNMap right(*g, INVALID); |
---|
| 575 | VecNode level_list(n,INVALID); |
---|
| 576 | //List of the nodes in level i<n, set to n. |
---|
[478] | 577 | |
---|
[485] | 578 | NodeIt v; |
---|
| 579 | for(g->first(v); g->valid(v); g->next(v)) level.set(v,n); |
---|
| 580 | //setting each node to level n |
---|
[478] | 581 | |
---|
[485] | 582 | switch ( fe ) { |
---|
| 583 | case PREFLOW: |
---|
| 584 | { |
---|
| 585 | //counting the excess |
---|
| 586 | NodeIt v; |
---|
| 587 | for(g->first(v); g->valid(v); g->next(v)) { |
---|
[478] | 588 | Num exc=0; |
---|
| 589 | |
---|
| 590 | InEdgeIt e; |
---|
[485] | 591 | for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e]; |
---|
[478] | 592 | OutEdgeIt f; |
---|
[485] | 593 | for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f]; |
---|
| 594 | |
---|
| 595 | excess.set(v,exc); |
---|
| 596 | |
---|
| 597 | //putting the active nodes into the stack |
---|
| 598 | int lev=level[v]; |
---|
| 599 | if ( exc > 0 && lev < n && v != t ) active[lev].push(v); |
---|
[478] | 600 | } |
---|
| 601 | break; |
---|
| 602 | } |
---|
[485] | 603 | case GEN_FLOW: |
---|
| 604 | { |
---|
| 605 | //Counting the excess of t |
---|
| 606 | Num exc=0; |
---|
| 607 | |
---|
| 608 | InEdgeIt e; |
---|
| 609 | for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e]; |
---|
| 610 | OutEdgeIt f; |
---|
| 611 | for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f]; |
---|
| 612 | |
---|
| 613 | excess.set(t,exc); |
---|
| 614 | |
---|
| 615 | break; |
---|
| 616 | } |
---|
| 617 | default: |
---|
| 618 | break; |
---|
| 619 | } |
---|
[478] | 620 | |
---|
[485] | 621 | preflowPreproc( fe, active, level_list, left, right ); |
---|
| 622 | //End of preprocessing |
---|
[478] | 623 | |
---|
| 624 | |
---|
[485] | 625 | //Push/relabel on the highest level active nodes. |
---|
| 626 | while ( true ) { |
---|
| 627 | if ( b == 0 ) { |
---|
| 628 | if ( !what_heur && !end && k > 0 ) { |
---|
| 629 | b=k; |
---|
| 630 | end=true; |
---|
| 631 | } else break; |
---|
| 632 | } |
---|
| 633 | |
---|
| 634 | if ( active[b].empty() ) --b; |
---|
| 635 | else { |
---|
| 636 | end=false; |
---|
| 637 | Node w=active[b].top(); |
---|
| 638 | active[b].pop(); |
---|
| 639 | int newlevel=push(w,active); |
---|
| 640 | if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list, |
---|
| 641 | left, right, b, k, what_heur); |
---|
| 642 | |
---|
| 643 | ++numrelabel; |
---|
| 644 | if ( numrelabel >= heur ) { |
---|
| 645 | numrelabel=0; |
---|
| 646 | if ( what_heur ) { |
---|
| 647 | what_heur=0; |
---|
| 648 | heur=heur0; |
---|
| 649 | end=false; |
---|
| 650 | } else { |
---|
| 651 | what_heur=1; |
---|
| 652 | heur=heur1; |
---|
| 653 | b=k; |
---|
| 654 | } |
---|
[478] | 655 | } |
---|
| 656 | } |
---|
[485] | 657 | } |
---|
| 658 | } |
---|
[478] | 659 | |
---|
| 660 | |
---|
| 661 | |
---|
| 662 | template <typename Graph, typename Num, typename CapMap, typename FlowMap> |
---|
| 663 | void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1() |
---|
| 664 | { |
---|
| 665 | |
---|
[485] | 666 | int k=n-2; //bound on the highest level under n containing a node |
---|
| 667 | int b=k; //bound on the highest level under n of an active node |
---|
[478] | 668 | |
---|
[485] | 669 | VecStack active(n); |
---|
| 670 | level.set(s,0); |
---|
| 671 | std::queue<Node> bfs_queue; |
---|
| 672 | bfs_queue.push(s); |
---|
[478] | 673 | |
---|
[485] | 674 | while (!bfs_queue.empty()) { |
---|
[478] | 675 | |
---|
[485] | 676 | Node v=bfs_queue.front(); |
---|
| 677 | bfs_queue.pop(); |
---|
| 678 | int l=level[v]+1; |
---|
[478] | 679 | |
---|
[485] | 680 | InEdgeIt e; |
---|
| 681 | for(g->first(e,v); g->valid(e); g->next(e)) { |
---|
| 682 | if ( (*capacity)[e] <= (*flow)[e] ) continue; |
---|
| 683 | Node u=g->tail(e); |
---|
| 684 | if ( level[u] >= n ) { |
---|
| 685 | bfs_queue.push(u); |
---|
| 686 | level.set(u, l); |
---|
| 687 | if ( excess[u] > 0 ) active[l].push(u); |
---|
[478] | 688 | } |
---|
| 689 | } |
---|
[485] | 690 | |
---|
| 691 | OutEdgeIt f; |
---|
| 692 | for(g->first(f,v); g->valid(f); g->next(f)) { |
---|
| 693 | if ( 0 >= (*flow)[f] ) continue; |
---|
| 694 | Node u=g->head(f); |
---|
| 695 | if ( level[u] >= n ) { |
---|
| 696 | bfs_queue.push(u); |
---|
| 697 | level.set(u, l); |
---|
| 698 | if ( excess[u] > 0 ) active[l].push(u); |
---|
| 699 | } |
---|
| 700 | } |
---|
| 701 | } |
---|
| 702 | b=n-2; |
---|
[478] | 703 | |
---|
[485] | 704 | while ( true ) { |
---|
[478] | 705 | |
---|
[485] | 706 | if ( b == 0 ) break; |
---|
[478] | 707 | |
---|
[485] | 708 | if ( active[b].empty() ) --b; |
---|
| 709 | else { |
---|
| 710 | Node w=active[b].top(); |
---|
| 711 | active[b].pop(); |
---|
| 712 | int newlevel=push(w,active); |
---|
[478] | 713 | |
---|
[485] | 714 | //relabel |
---|
| 715 | if ( excess[w] > 0 ) { |
---|
| 716 | level.set(w,++newlevel); |
---|
| 717 | active[newlevel].push(w); |
---|
| 718 | b=newlevel; |
---|
| 719 | } |
---|
| 720 | } // if stack[b] is nonempty |
---|
| 721 | } // while(true) |
---|
| 722 | } |
---|
[478] | 723 | |
---|
| 724 | |
---|
| 725 | |
---|
| 726 | template <typename Graph, typename Num, typename CapMap, typename FlowMap> |
---|
| 727 | bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath() |
---|
| 728 | { |
---|
[485] | 729 | ResGW res_graph(*g, *capacity, *flow); |
---|
| 730 | bool _augment=false; |
---|
[478] | 731 | |
---|
[485] | 732 | //ReachedMap level(res_graph); |
---|
| 733 | FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0); |
---|
| 734 | BfsIterator<ResGW, ReachedMap> bfs(res_graph, level); |
---|
| 735 | bfs.pushAndSetReached(s); |
---|
[478] | 736 | |
---|
[485] | 737 | typename ResGW::template NodeMap<ResGWEdge> pred(res_graph); |
---|
| 738 | pred.set(s, INVALID); |
---|
[478] | 739 | |
---|
[485] | 740 | typename ResGW::template NodeMap<Num> free(res_graph); |
---|
[478] | 741 | |
---|
[485] | 742 | //searching for augmenting path |
---|
| 743 | while ( !bfs.finished() ) { |
---|
| 744 | ResGWOutEdgeIt e=bfs; |
---|
| 745 | if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) { |
---|
| 746 | Node v=res_graph.tail(e); |
---|
| 747 | Node w=res_graph.head(e); |
---|
| 748 | pred.set(w, e); |
---|
| 749 | if (res_graph.valid(pred[v])) { |
---|
| 750 | free.set(w, std::min(free[v], res_graph.resCap(e))); |
---|
| 751 | } else { |
---|
| 752 | free.set(w, res_graph.resCap(e)); |
---|
[478] | 753 | } |
---|
[485] | 754 | if (res_graph.head(e)==t) { _augment=true; break; } |
---|
| 755 | } |
---|
[478] | 756 | |
---|
[485] | 757 | ++bfs; |
---|
| 758 | } //end of searching augmenting path |
---|
[478] | 759 | |
---|
[485] | 760 | if (_augment) { |
---|
| 761 | Node n=t; |
---|
| 762 | Num augment_value=free[t]; |
---|
| 763 | while (res_graph.valid(pred[n])) { |
---|
| 764 | ResGWEdge e=pred[n]; |
---|
| 765 | res_graph.augment(e, augment_value); |
---|
| 766 | n=res_graph.tail(e); |
---|
[478] | 767 | } |
---|
[485] | 768 | } |
---|
[478] | 769 | |
---|
[485] | 770 | return _augment; |
---|
| 771 | } |
---|
[478] | 772 | |
---|
| 773 | |
---|
| 774 | |
---|
| 775 | |
---|
| 776 | |
---|
| 777 | |
---|
| 778 | |
---|
| 779 | |
---|
| 780 | |
---|
| 781 | template <typename Graph, typename Num, typename CapMap, typename FlowMap> |
---|
| 782 | template<typename MutableGraph> |
---|
| 783 | bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow() |
---|
| 784 | { |
---|
[485] | 785 | typedef MutableGraph MG; |
---|
| 786 | bool _augment=false; |
---|
[478] | 787 | |
---|
[485] | 788 | ResGW res_graph(*g, *capacity, *flow); |
---|
[478] | 789 | |
---|
[485] | 790 | //bfs for distances on the residual graph |
---|
| 791 | //ReachedMap level(res_graph); |
---|
| 792 | FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0); |
---|
| 793 | BfsIterator<ResGW, ReachedMap> bfs(res_graph, level); |
---|
| 794 | bfs.pushAndSetReached(s); |
---|
| 795 | typename ResGW::template NodeMap<int> |
---|
| 796 | dist(res_graph); //filled up with 0's |
---|
[478] | 797 | |
---|
[485] | 798 | //F will contain the physical copy of the residual graph |
---|
| 799 | //with the set of edges which are on shortest paths |
---|
| 800 | MG F; |
---|
| 801 | typename ResGW::template NodeMap<typename MG::Node> |
---|
| 802 | res_graph_to_F(res_graph); |
---|
| 803 | { |
---|
| 804 | typename ResGW::NodeIt n; |
---|
| 805 | for(res_graph.first(n); res_graph.valid(n); res_graph.next(n)) { |
---|
| 806 | res_graph_to_F.set(n, F.addNode()); |
---|
[478] | 807 | } |
---|
[485] | 808 | } |
---|
[478] | 809 | |
---|
[485] | 810 | typename MG::Node sF=res_graph_to_F[s]; |
---|
| 811 | typename MG::Node tF=res_graph_to_F[t]; |
---|
| 812 | typename MG::template EdgeMap<ResGWEdge> original_edge(F); |
---|
| 813 | typename MG::template EdgeMap<Num> residual_capacity(F); |
---|
[478] | 814 | |
---|
[485] | 815 | while ( !bfs.finished() ) { |
---|
| 816 | ResGWOutEdgeIt e=bfs; |
---|
| 817 | if (res_graph.valid(e)) { |
---|
| 818 | if (bfs.isBNodeNewlyReached()) { |
---|
| 819 | dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1); |
---|
| 820 | typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]); |
---|
| 821 | original_edge.update(); |
---|
| 822 | original_edge.set(f, e); |
---|
| 823 | residual_capacity.update(); |
---|
| 824 | residual_capacity.set(f, res_graph.resCap(e)); |
---|
| 825 | } else { |
---|
| 826 | if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) { |
---|
[478] | 827 | typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]); |
---|
| 828 | original_edge.update(); |
---|
| 829 | original_edge.set(f, e); |
---|
| 830 | residual_capacity.update(); |
---|
| 831 | residual_capacity.set(f, res_graph.resCap(e)); |
---|
| 832 | } |
---|
| 833 | } |
---|
[485] | 834 | } |
---|
| 835 | ++bfs; |
---|
| 836 | } //computing distances from s in the residual graph |
---|
[478] | 837 | |
---|
[485] | 838 | bool __augment=true; |
---|
[478] | 839 | |
---|
[485] | 840 | while (__augment) { |
---|
| 841 | __augment=false; |
---|
| 842 | //computing blocking flow with dfs |
---|
| 843 | DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F); |
---|
| 844 | typename MG::template NodeMap<typename MG::Edge> pred(F); |
---|
| 845 | pred.set(sF, INVALID); |
---|
| 846 | //invalid iterators for sources |
---|
[478] | 847 | |
---|
[485] | 848 | typename MG::template NodeMap<Num> free(F); |
---|
[478] | 849 | |
---|
[485] | 850 | dfs.pushAndSetReached(sF); |
---|
| 851 | while (!dfs.finished()) { |
---|
| 852 | ++dfs; |
---|
| 853 | if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) { |
---|
| 854 | if (dfs.isBNodeNewlyReached()) { |
---|
| 855 | typename MG::Node v=F.aNode(dfs); |
---|
| 856 | typename MG::Node w=F.bNode(dfs); |
---|
| 857 | pred.set(w, dfs); |
---|
| 858 | if (F.valid(pred[v])) { |
---|
| 859 | free.set(w, std::min(free[v], residual_capacity[dfs])); |
---|
| 860 | } else { |
---|
| 861 | free.set(w, residual_capacity[dfs]); |
---|
| 862 | } |
---|
| 863 | if (w==tF) { |
---|
| 864 | __augment=true; |
---|
| 865 | _augment=true; |
---|
| 866 | break; |
---|
| 867 | } |
---|
[478] | 868 | |
---|
[485] | 869 | } else { |
---|
| 870 | F.erase(/*typename MG::OutEdgeIt*/(dfs)); |
---|
| 871 | } |
---|
| 872 | } |
---|
| 873 | } |
---|
| 874 | |
---|
| 875 | if (__augment) { |
---|
| 876 | typename MG::Node n=tF; |
---|
| 877 | Num augment_value=free[tF]; |
---|
| 878 | while (F.valid(pred[n])) { |
---|
| 879 | typename MG::Edge e=pred[n]; |
---|
| 880 | res_graph.augment(original_edge[e], augment_value); |
---|
| 881 | n=F.tail(e); |
---|
| 882 | if (residual_capacity[e]==augment_value) |
---|
| 883 | F.erase(e); |
---|
| 884 | else |
---|
| 885 | residual_capacity.set(e, residual_capacity[e]-augment_value); |
---|
[478] | 886 | } |
---|
[485] | 887 | } |
---|
[478] | 888 | |
---|
[485] | 889 | } |
---|
[478] | 890 | |
---|
[485] | 891 | return _augment; |
---|
| 892 | } |
---|
[478] | 893 | |
---|
| 894 | |
---|
| 895 | |
---|
| 896 | |
---|
| 897 | |
---|
| 898 | |
---|
| 899 | template <typename Graph, typename Num, typename CapMap, typename FlowMap> |
---|
| 900 | bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2() |
---|
| 901 | { |
---|
[485] | 902 | bool _augment=false; |
---|
[478] | 903 | |
---|
[485] | 904 | ResGW res_graph(*g, *capacity, *flow); |
---|
[478] | 905 | |
---|
[485] | 906 | //ReachedMap level(res_graph); |
---|
| 907 | FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0); |
---|
| 908 | BfsIterator<ResGW, ReachedMap> bfs(res_graph, level); |
---|
[478] | 909 | |
---|
[485] | 910 | bfs.pushAndSetReached(s); |
---|
| 911 | DistanceMap<ResGW> dist(res_graph); |
---|
| 912 | while ( !bfs.finished() ) { |
---|
| 913 | ResGWOutEdgeIt e=bfs; |
---|
| 914 | if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) { |
---|
| 915 | dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1); |
---|
| 916 | } |
---|
| 917 | ++bfs; |
---|
| 918 | } //computing distances from s in the residual graph |
---|
[478] | 919 | |
---|
| 920 | //Subgraph containing the edges on some shortest paths |
---|
[485] | 921 | ConstMap<typename ResGW::Node, bool> true_map(true); |
---|
| 922 | typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>, |
---|
| 923 | DistanceMap<ResGW> > FilterResGW; |
---|
| 924 | FilterResGW filter_res_graph(res_graph, true_map, dist); |
---|
[478] | 925 | |
---|
[485] | 926 | //Subgraph, which is able to delete edges which are already |
---|
| 927 | //met by the dfs |
---|
| 928 | typename FilterResGW::template NodeMap<typename FilterResGW::OutEdgeIt> |
---|
| 929 | first_out_edges(filter_res_graph); |
---|
| 930 | typename FilterResGW::NodeIt v; |
---|
| 931 | for(filter_res_graph.first(v); filter_res_graph.valid(v); |
---|
| 932 | filter_res_graph.next(v)) |
---|
[478] | 933 | { |
---|
| 934 | typename FilterResGW::OutEdgeIt e; |
---|
| 935 | filter_res_graph.first(e, v); |
---|
| 936 | first_out_edges.set(v, e); |
---|
| 937 | } |
---|
[485] | 938 | typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW:: |
---|
| 939 | template NodeMap<typename FilterResGW::OutEdgeIt> > ErasingResGW; |
---|
| 940 | ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges); |
---|
[478] | 941 | |
---|
[485] | 942 | bool __augment=true; |
---|
[478] | 943 | |
---|
[485] | 944 | while (__augment) { |
---|
[478] | 945 | |
---|
[485] | 946 | __augment=false; |
---|
| 947 | //computing blocking flow with dfs |
---|
| 948 | DfsIterator< ErasingResGW, |
---|
| 949 | typename ErasingResGW::template NodeMap<bool> > |
---|
| 950 | dfs(erasing_res_graph); |
---|
| 951 | typename ErasingResGW:: |
---|
| 952 | template NodeMap<typename ErasingResGW::OutEdgeIt> |
---|
| 953 | pred(erasing_res_graph); |
---|
| 954 | pred.set(s, INVALID); |
---|
| 955 | //invalid iterators for sources |
---|
[478] | 956 | |
---|
[485] | 957 | typename ErasingResGW::template NodeMap<Num> |
---|
| 958 | free1(erasing_res_graph); |
---|
[478] | 959 | |
---|
[485] | 960 | dfs.pushAndSetReached( |
---|
| 961 | typename ErasingResGW::Node( |
---|
| 962 | typename FilterResGW::Node( |
---|
| 963 | typename ResGW::Node(s) |
---|
| 964 | ) |
---|
| 965 | ) |
---|
| 966 | ); |
---|
| 967 | while (!dfs.finished()) { |
---|
| 968 | ++dfs; |
---|
| 969 | if (erasing_res_graph.valid( |
---|
| 970 | typename ErasingResGW::OutEdgeIt(dfs))) |
---|
[478] | 971 | { |
---|
| 972 | if (dfs.isBNodeNewlyReached()) { |
---|
| 973 | |
---|
| 974 | typename ErasingResGW::Node v=erasing_res_graph.aNode(dfs); |
---|
| 975 | typename ErasingResGW::Node w=erasing_res_graph.bNode(dfs); |
---|
| 976 | |
---|
| 977 | pred.set(w, /*typename ErasingResGW::OutEdgeIt*/(dfs)); |
---|
| 978 | if (erasing_res_graph.valid(pred[v])) { |
---|
| 979 | free1.set(w, std::min(free1[v], res_graph.resCap( |
---|
[485] | 980 | typename ErasingResGW::OutEdgeIt(dfs)))); |
---|
[478] | 981 | } else { |
---|
| 982 | free1.set(w, res_graph.resCap( |
---|
[485] | 983 | typename ErasingResGW::OutEdgeIt(dfs))); |
---|
[478] | 984 | } |
---|
| 985 | |
---|
| 986 | if (w==t) { |
---|
| 987 | __augment=true; |
---|
| 988 | _augment=true; |
---|
| 989 | break; |
---|
| 990 | } |
---|
| 991 | } else { |
---|
| 992 | erasing_res_graph.erase(dfs); |
---|
| 993 | } |
---|
| 994 | } |
---|
[485] | 995 | } |
---|
[478] | 996 | |
---|
[485] | 997 | if (__augment) { |
---|
| 998 | typename ErasingResGW::Node n=typename FilterResGW::Node(typename ResGW::Node(t)); |
---|
| 999 | // typename ResGW::NodeMap<Num> a(res_graph); |
---|
| 1000 | // typename ResGW::Node b; |
---|
| 1001 | // Num j=a[b]; |
---|
| 1002 | // typename FilterResGW::NodeMap<Num> a1(filter_res_graph); |
---|
| 1003 | // typename FilterResGW::Node b1; |
---|
| 1004 | // Num j1=a1[b1]; |
---|
| 1005 | // typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph); |
---|
| 1006 | // typename ErasingResGW::Node b2; |
---|
| 1007 | // Num j2=a2[b2]; |
---|
| 1008 | Num augment_value=free1[n]; |
---|
| 1009 | while (erasing_res_graph.valid(pred[n])) { |
---|
| 1010 | typename ErasingResGW::OutEdgeIt e=pred[n]; |
---|
| 1011 | res_graph.augment(e, augment_value); |
---|
| 1012 | n=erasing_res_graph.tail(e); |
---|
| 1013 | if (res_graph.resCap(e)==0) |
---|
| 1014 | erasing_res_graph.erase(e); |
---|
[478] | 1015 | } |
---|
| 1016 | } |
---|
| 1017 | |
---|
[485] | 1018 | } //while (__augment) |
---|
[478] | 1019 | |
---|
[485] | 1020 | return _augment; |
---|
| 1021 | } |
---|
[478] | 1022 | |
---|
| 1023 | |
---|
| 1024 | |
---|
| 1025 | |
---|
| 1026 | } //namespace hugo |
---|
| 1027 | |
---|
[480] | 1028 | #endif //HUGO_MAX_FLOW_H |
---|
[478] | 1029 | |
---|
| 1030 | |
---|
| 1031 | |
---|
| 1032 | |
---|