Changeset 891:bb70ad62c95f in lemon-main

Timestamp:

06/24/10 09:27:53 (14 years ago)

Author:

Balazs Dezso <deba@…>

Branch:

default

Children:

892:a22b3f1bf83e, 923:30d5f950aa5f

Phase:

public

Message:

Fix critical bug in preflow (#372)

The wrong transition between the bound decrease and highest active
heuristics caused the bug. The last node chosen in bound decrease mode
is used in the first iteration in highest active mode.

File:

• lemon/preflow.h (modified) (3 diffs)

lemon/preflow.h

@@ -559 +559 @@
       _phase = true;
 
-      Node n = _level->highestActive();
-      int level = _level->highestActiveLevel();
-      while (n != INVALID) {
+      while (true) {
         int num = _node_num;
 
-        while (num > 0 && n != INVALID) {
+        Node n = INVALID;
+        int level = -1;
+
+        while (num > 0) {
+          n = _level->highestActive();
+          if (n == INVALID) goto first_phase_done;
+          level = _level->highestActiveLevel();
+          --num;
+          
           Value excess = (*_excess)[n];
           int new_level = _level->maxLevel();
@@ -630 +636 @@
             _level->deactivate(n);
           }
-
-          n = _level->highestActive();
-          level = _level->highestActiveLevel();
+        }
+
+        num = _node_num * 20;
+        while (num > 0) {
+          while (level >= 0 && _level->activeFree(level)) {
+            --level;
+          }
+          if (level == -1) {
+            n = _level->highestActive();
+            level = _level->highestActiveLevel();
+            if (n == INVALID) goto first_phase_done;
+          } else {
+            n = _level->activeOn(level);
+          }
           --num;
-        }
-
-        num = _node_num * 20;
-        while (num > 0 && n != INVALID) {
+
           Value excess = (*_excess)[n];
           int new_level = _level->maxLevel();
@@ -703 +717 @@
             _level->deactivate(n);
           }
-
-          while (level >= 0 && _level->activeFree(level)) {
-            --level;
-          }
-          if (level == -1) {
-            n = _level->highestActive();
-            level = _level->highestActiveLevel();
-          } else {
-            n = _level->activeOn(level);
-          }
-          --num;
-        }
-      }
+        }
+      }
+    first_phase_done:;
     }