gravatar
kpeter (Peter Kovacs)
kpeter@inf.elte.hu
Simplify comparisons in min mean cycle classes (#179) using extreme INF values instead of bool flags.
0 3 0
default
3 files changed with 50 insertions and 39 deletions:
↑ Collapse diff ↑
Ignore white space 6 line context
... ...
@@ -150,11 +150,10 @@
150 150
    // Data sturcture for path data
151 151
    struct PathData
152 152
    {
153
      bool found;
154 153
      LargeValue dist;
155 154
      Arc pred;
156
      PathData(bool f = false, LargeValue d = 0, Arc p = INVALID) :
157
        found(f), dist(d), pred(p) {}
155
      PathData(LargeValue d, Arc p = INVALID) :
156
        dist(d), pred(p) {}
158 157
    };
159 158

	
160 159
    typedef typename Digraph::template NodeMap<std::vector<PathData> >
... ...
@@ -191,6 +190,9 @@
191 190

	
192 191
    Tolerance _tolerance;
193 192

	
193
    // Infinite constant
194
    const LargeValue INF;
195

	
194 196
  public:
195 197

	
196 198
    /// \name Named Template Parameters
... ...
@@ -245,7 +247,10 @@
245 247
                   const LengthMap &length ) :
246 248
      _gr(digraph), _length(length), _comp(digraph), _out_arcs(digraph),
247 249
      _best_found(false), _best_length(0), _best_size(1),
248
      _cycle_path(NULL), _local_path(false), _data(digraph)
250
      _cycle_path(NULL), _local_path(false), _data(digraph),
251
      INF(std::numeric_limits<LargeValue>::has_infinity ?
252
          std::numeric_limits<LargeValue>::infinity() :
253
          std::numeric_limits<LargeValue>::max())
249 254
    {}
250 255

	
251 256
    /// Destructor.
... ...
@@ -472,7 +477,7 @@
472 477
        return false;
473 478
      }      
474 479
      for (int i = 0; i < n; ++i) {
475
        _data[(*_nodes)[i]].resize(n + 1);
480
        _data[(*_nodes)[i]].resize(n + 1, PathData(INF));
476 481
      }
477 482
      return true;
478 483
    }
... ...
@@ -482,7 +487,7 @@
482 487
    // node to node v containing exactly k arcs.
483 488
    void processRounds() {
484 489
      Node start = (*_nodes)[0];
485
      _data[start][0] = PathData(true, 0);
490
      _data[start][0] = PathData(0);
486 491
      _process.clear();
487 492
      _process.push_back(start);
488 493

	
... ...
@@ -517,12 +522,9 @@
517 522
          e = _out_arcs[u][j];
518 523
          v = _gr.target(e);
519 524
          d = _data[u][k-1].dist + _length[e];
520
          if (!_data[v][k].found) {
521
            next.push_back(v);
522
            _data[v][k] = PathData(true, _data[u][k-1].dist + _length[e], e);
523
          }
524
          else if (_tolerance.less(d, _data[v][k].dist)) {
525
            _data[v][k] = PathData(true, d, e);
525
          if (_tolerance.less(d, _data[v][k].dist)) {
526
            if (_data[v][k].dist == INF) next.push_back(v);
527
            _data[v][k] = PathData(d, e);
526 528
          }
527 529
        }
528 530
      }
... ...
@@ -540,8 +542,8 @@
540 542
          e = _out_arcs[u][j];
541 543
          v = _gr.target(e);
542 544
          d = _data[u][k-1].dist + _length[e];
543
          if (!_data[v][k].found || _tolerance.less(d, _data[v][k].dist)) {
544
            _data[v][k] = PathData(true, d, e);
545
          if (_tolerance.less(d, _data[v][k].dist)) {
546
            _data[v][k] = PathData(d, e);
545 547
          }
546 548
        }
547 549
      }
... ...
@@ -561,7 +563,7 @@
561 563
      _curr_found = false;
562 564
      for (int i = 0; i < n; ++i) {
563 565
        u = (*_nodes)[i];
564
        if (!_data[u][k].found) continue;
566
        if (_data[u][k].dist == INF) continue;
565 567
        for (int j = k; j >= 0; --j) {
566 568
          if (level[u].first == i && level[u].second > 0) {
567 569
            // A cycle is found
... ...
@@ -586,11 +588,11 @@
586 588
        // Find node potentials
587 589
        for (int i = 0; i < n; ++i) {
588 590
          u = (*_nodes)[i];
589
          pi[u] = std::numeric_limits<LargeValue>::max();
591
          pi[u] = INF;
590 592
          for (int j = 0; j <= k; ++j) {
591
            d = _data[u][j].dist * _curr_size - j * _curr_length;
592
            if (_data[u][j].found && _tolerance.less(d, pi[u])) {
593
              pi[u] = d;
593
            if (_data[u][j].dist < INF) {
594
              d = _data[u][j].dist * _curr_size - j * _curr_length;
595
              if (_tolerance.less(d, pi[u])) pi[u] = d;
594 596
            }
595 597
          }
596 598
        }
Ignore white space 6 line context
... ...
@@ -178,6 +178,9 @@
178 178

	
179 179
    Tolerance _tolerance;
180 180
  
181
    // Infinite constant
182
    const LargeValue INF;
183

	
181 184
  public:
182 185
  
183 186
    /// \name Named Template Parameters
... ...
@@ -230,9 +233,13 @@
230 233
    /// \param length The lengths (costs) of the arcs.
231 234
    Howard( const Digraph &digraph,
232 235
            const LengthMap &length ) :
233
      _gr(digraph), _length(length), _cycle_path(NULL), _local_path(false),
236
      _gr(digraph), _length(length), _best_found(false),
237
      _best_length(0), _best_size(1), _cycle_path(NULL), _local_path(false),
234 238
      _policy(digraph), _reached(digraph), _level(digraph), _dist(digraph),
235
      _comp(digraph), _in_arcs(digraph)
239
      _comp(digraph), _in_arcs(digraph),
240
      INF(std::numeric_limits<LargeValue>::has_infinity ?
241
          std::numeric_limits<LargeValue>::infinity() :
242
          std::numeric_limits<LargeValue>::max())
236 243
    {}
237 244

	
238 245
    /// Destructor.
... ...
@@ -307,7 +314,7 @@
307 314
          if (!computeNodeDistances()) break;
308 315
        }
309 316
        // Update the best cycle (global minimum mean cycle)
310
        if ( !_best_found || (_curr_found &&
317
        if ( _curr_found && (!_best_found ||
311 318
             _curr_length * _best_size < _best_length * _curr_size) ) {
312 319
          _best_found = true;
313 320
          _best_length = _curr_length;
... ...
@@ -446,7 +453,7 @@
446 453
        return false;
447 454
      }
448 455
      for (int i = 0; i < int(_nodes->size()); ++i) {
449
        _dist[(*_nodes)[i]] = std::numeric_limits<LargeValue>::max();
456
        _dist[(*_nodes)[i]] = INF;
450 457
      }
451 458
      Node u, v;
452 459
      Arc e;
Ignore white space 6 line context
... ...
@@ -148,11 +148,10 @@
148 148
    // Data sturcture for path data
149 149
    struct PathData
150 150
    {
151
      bool found;
152 151
      LargeValue dist;
153 152
      Arc pred;
154
      PathData(bool f = false, LargeValue d = 0, Arc p = INVALID) :
155
        found(f), dist(d), pred(p) {}
153
      PathData(LargeValue d, Arc p = INVALID) :
154
        dist(d), pred(p) {}
156 155
    };
157 156

	
158 157
    typedef typename Digraph::template NodeMap<std::vector<PathData> >
... ...
@@ -186,6 +185,9 @@
186 185
    std::vector<Node> _process;
187 186

	
188 187
    Tolerance _tolerance;
188
    
189
    // Infinite constant
190
    const LargeValue INF;
189 191

	
190 192
  public:
191 193

	
... ...
@@ -241,7 +243,10 @@
241 243
          const LengthMap &length ) :
242 244
      _gr(digraph), _length(length), _comp(digraph), _out_arcs(digraph),
243 245
      _cycle_length(0), _cycle_size(1), _cycle_node(INVALID),
244
      _cycle_path(NULL), _local_path(false), _data(digraph)
246
      _cycle_path(NULL), _local_path(false), _data(digraph),
247
      INF(std::numeric_limits<LargeValue>::has_infinity ?
248
          std::numeric_limits<LargeValue>::infinity() :
249
          std::numeric_limits<LargeValue>::max())
245 250
    {}
246 251

	
247 252
    /// Destructor.
... ...
@@ -458,7 +463,7 @@
458 463
        return false;
459 464
      }      
460 465
      for (int i = 0; i < n; ++i) {
461
        _data[(*_nodes)[i]].resize(n + 1);
466
        _data[(*_nodes)[i]].resize(n + 1, PathData(INF));
462 467
      }
463 468
      return true;
464 469
    }
... ...
@@ -468,7 +473,7 @@
468 473
    // node to node v containing exactly k arcs.
469 474
    void processRounds() {
470 475
      Node start = (*_nodes)[0];
471
      _data[start][0] = PathData(true, 0);
476
      _data[start][0] = PathData(0);
472 477
      _process.clear();
473 478
      _process.push_back(start);
474 479

	
... ...
@@ -493,12 +498,9 @@
493 498
          e = _out_arcs[u][j];
494 499
          v = _gr.target(e);
495 500
          d = _data[u][k-1].dist + _length[e];
496
          if (!_data[v][k].found) {
497
            next.push_back(v);
498
            _data[v][k] = PathData(true, _data[u][k-1].dist + _length[e], e);
499
          }
500
          else if (_tolerance.less(d, _data[v][k].dist)) {
501
            _data[v][k] = PathData(true, d, e);
501
          if (_tolerance.less(d, _data[v][k].dist)) {
502
            if (_data[v][k].dist == INF) next.push_back(v);
503
            _data[v][k] = PathData(d, e);
502 504
          }
503 505
        }
504 506
      }
... ...
@@ -516,8 +518,8 @@
516 518
          e = _out_arcs[u][j];
517 519
          v = _gr.target(e);
518 520
          d = _data[u][k-1].dist + _length[e];
519
          if (!_data[v][k].found || _tolerance.less(d, _data[v][k].dist)) {
520
            _data[v][k] = PathData(true, d, e);
521
          if (_tolerance.less(d, _data[v][k].dist)) {
522
            _data[v][k] = PathData(d, e);
521 523
          }
522 524
        }
523 525
      }
... ...
@@ -528,12 +530,12 @@
528 530
      int n = _nodes->size();
529 531
      for (int i = 0; i < n; ++i) {
530 532
        Node u = (*_nodes)[i];
531
        if (!_data[u][n].found) continue;
533
        if (_data[u][n].dist == INF) continue;
532 534
        LargeValue length, max_length = 0;
533 535
        int size, max_size = 1;
534 536
        bool found_curr = false;
535 537
        for (int k = 0; k < n; ++k) {
536
          if (!_data[u][k].found) continue;
538
          if (_data[u][k].dist == INF) continue;
537 539
          length = _data[u][n].dist - _data[u][k].dist;
538 540
          size = n - k;
539 541
          if (!found_curr || length * max_size > max_length * size) {
0 comments (0 inline)