Do not skip states if approx = 0.0

Former-commit-id: 37dbb9739c

src/builder/ExplicitDFTModelBuilderApprox.cpp

@@ -143,6 +143,7 @@ namespace storm {
                 initializeNextIteration();
             }
 
+            if (approximationThreshold > 0) {
                 switch (heuristic) {
                     case storm::builder::ApproximationHeuristic::NONE:
                         // Do not change anything
@@ -155,6 +156,7 @@ namespace storm {
                         approximationThreshold = 10 * std::pow(2, iteration);
                         break;
                 }
+            }
             exploreStateSpace(approximationThreshold);
 
             size_t stateSize = stateStorage.getNumberOfStates() + (mergeFailedStates ? 1 : 0);
@@ -319,7 +321,7 @@ namespace storm {
                 // Try to explore the next state
                 generator.load(currentState);
 
-                if (nrExpandedStates > approximationThreshold && !currentExplorationHeuristic->isExpand()) {
+                if (approximationThreshold > 0.0 && nrExpandedStates > approximationThreshold && !currentExplorationHeuristic->isExpand()) {
                 //if (currentExplorationHeuristic->isSkip(approximationThreshold)) {
                     // Skip the current state
                     ++nrSkippedStates;