Fix typo, improve debuggung

src/main/java/de/uni/bremen/grapa/library/algorithms/vertexcover/NativeVcSolver.java

@@ -3,6 +3,8 @@ package de.uni.bremen.grapa.library.algorithms.vertexcover;
 import de.uni.bremen.grapa.library.graphs.api.DirectedEdge;
 import de.uni.bremen.grapa.library.graphs.api.DirectedGraph;
 import de.uni.bremen.grapa.library.graphs.api.Vertex;
+import de.uni.bremen.grapa.library.helper.GraphRenaming;
+import de.uni.bremen.grapa.library.helper.GraphRenamingResult;
 
 import java.io.BufferedInputStream;
 import java.io.File;
@@ -58,11 +60,14 @@ public class NativeVcSolver {
 
         try {
             final Process process = processBuilder.start();
-            final int offset = graph.vertexExists(0) ? 1 : 0;
+            final int offset = 1;
 
-            writeProblem(process, graph, offset);
+            GraphRenamingResult renaming = new GraphRenaming().rename(graph);
+            writeProblem(process, renaming.renamedGraph(), offset);
 
-            return readResult(graph, process, offset);
+            Set<Vertex> result = readResult(renaming.renamedGraph(), process, offset);
+
+            return renaming.decipher(result);
         } catch (IOException e) {
             e.printStackTrace();
             throw new IllegalStateException("VC Solver not successful");