1 files changed, 104 insertions, 0 deletions
diff --git a/common/utility/CombinadicIterator.C b/common/utility/CombinadicIterator.C
new file mode 100644
index 0000000..15152cb
--- /dev/null
+++ b/common/utility/CombinadicIterator.C
@@ -0,0 +1,104 @@
+// Copyright 2008, 2009 Brady J. Garvin
+
+// This file is part of Covering Arrays by Simulated Annealing (CASA).
+
+// CASA is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// CASA is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with CASA.  If not, see <http://www.gnu.org/licenses/>.
+
+
+#include <cassert>
+#include <algorithm>
+
+#include "CombinadicIterator.H"
+
+using namespace std;
+
+CombinadicIterator::CombinadicIterator
+  (unsigned populationSize, unsigned sampleSize, Array<unsigned>relevant) :
+  populationSize(populationSize),
+  relevant(relevant),
+  notRelevant(populationSize - relevant.getSize()),
+  minimumRelevance(max((int)sampleSize - (int)notRelevant.getSize(), 1)),
+  maximumRelevance(min(relevant.getSize(), sampleSize)),
+  choiceFromRelevant(combinadic.begin(maximumRelevance)),
+  choiceFromNotRelevant(combinadic.begin(sampleSize - maximumRelevance)),
+  relevantCombination(sampleSize),
+  combination(sampleSize) {
+  assert(sampleSize <= populationSize);
+  for (unsigned i = 0, j = 0, k = 0; i < notRelevant.getSize(); ++i, ++j) {
+    while (k < relevant.getSize() && relevant[k] == j) {
+      ++j;
+      ++k;
+    }
+    notRelevant[i] = j;
+  }
+  updateCombinationFromRelevant();
+  updateCombination();
+}
+
+void CombinadicIterator::updateCombinationFromRelevant() {
+  for (unsigned i = maximumRelevance; i--;) {
+    relevantCombination[i] = relevant[choiceFromRelevant[i]];
+  }
+}
+
+void CombinadicIterator::updateCombination() {
+  for (unsigned i = combination.getSize(); i-- > maximumRelevance;) {
+    combination[i] = notRelevant[choiceFromNotRelevant[i - maximumRelevance]];
+  }
+  for (unsigned i = maximumRelevance; i--;) {
+    combination[i] = relevantCombination[i];
+  }
+  sort(combination + 0, combination + combination.getSize());
+}
+
+const Array<unsigned>CombinadicIterator::operator *() const {
+#ifndef NDEBUG
+  for (unsigned i = combination.getSize(); --i;) {
+    assert(combination[i - 1] < combination[i]);
+  }
+#endif
+  return combination;
+}
+
+CombinadicIterator::operator bool() const {
+  return combination.getSize();
+}
+
+CombinadicIterator&CombinadicIterator::operator ++() {
+  if (!combination.getSize()) {
+    return *this;
+  }
+  bool someFromNotRelevant = choiceFromNotRelevant.getSize();
+  if (someFromNotRelevant) {
+    combinadic.next(choiceFromNotRelevant);
+  }
+  if (!someFromNotRelevant ||
+      choiceFromNotRelevant[choiceFromNotRelevant.getSize() - 1] >=
+      populationSize - relevant.getSize()) {
+    combinadic.next(choiceFromRelevant);
+    if (choiceFromRelevant[maximumRelevance - 1] >= relevant.getSize()) {
+      --maximumRelevance;
+      if (maximumRelevance < minimumRelevance) {
+	combination = Array<unsigned>(0);
+	return *this;
+      }
+      choiceFromRelevant = combinadic.begin(maximumRelevance);
+    }
+    updateCombinationFromRelevant();
+    choiceFromNotRelevant =
+      combinadic.begin(combination.getSize() - maximumRelevance);
+  }
+  updateCombination();
+  return *this;
+}