Minor changes for predictable ordering (jgrapht#1078)

AlexOcculate · Apr 28, 2021 · ffb5e50 · ffb5e50
1 parent 37f2b43
commit ffb5e50
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Showing 4 changed files with 27 additions and 15 deletions.
diff --git a/jgrapht-core/src/main/java/org/jgrapht/alg/partition/BipartitePartitioning.java b/jgrapht-core/src/main/java/org/jgrapht/alg/partition/BipartitePartitioning.java
@@ -92,8 +92,8 @@ public Partitioning<V> getPartitioning()
             return cachedPartitioning;
         }
 
-        Set<V> unknown = new HashSet<>(graph.vertexSet());
-        Set<V> odd = new HashSet<>();
+        Set<V> unknown = new LinkedHashSet<>(graph.vertexSet());
+        Set<V> odd = new LinkedHashSet<>();
         Deque<V> queue = new ArrayDeque<>();
 
         while (!unknown.isEmpty()) {
@@ -119,7 +119,7 @@ public Partitioning<V> getPartitioning()
             }
         }
 
-        Set<V> even = new HashSet<>(graph.vertexSet());
+        Set<V> even = new LinkedHashSet<>(graph.vertexSet());
         even.removeAll(odd);
 
         computed = true;

diff --git a/jgrapht-core/src/main/java/org/jgrapht/traverse/DegeneracyOrderingIterator.java b/jgrapht-core/src/main/java/org/jgrapht/traverse/DegeneracyOrderingIterator.java
@@ -17,10 +17,15 @@
  */
 package org.jgrapht.traverse;
 
-import org.jgrapht.*;
+import java.lang.reflect.Array;
+import java.util.HashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Set;
 
-import java.lang.reflect.*;
-import java.util.*;
+import org.jgrapht.Graph;
+import org.jgrapht.Graphs;
 
 /**
  * A degeneracy ordering iterator.
@@ -88,7 +93,7 @@ public DegeneracyOrderingIterator(Graph<V, E> graph)
          */
         this.buckets = (Set<V>[]) Array.newInstance(Set.class, maxDegree + 1);
         for (int i = 0; i < buckets.length; i++) {
-            buckets[i] = new HashSet<>();
+            buckets[i] = new LinkedHashSet<>();
         }
         for (V v : graph.vertexSet()) {
             buckets[degrees.get(v)].add(v);

diff --git a/jgrapht-core/src/main/java/org/jgrapht/traverse/LexBreadthFirstIterator.java b/jgrapht-core/src/main/java/org/jgrapht/traverse/LexBreadthFirstIterator.java
@@ -17,10 +17,17 @@
  */
 package org.jgrapht.traverse;
 
-import org.jgrapht.*;
-import org.jgrapht.util.*;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Set;
 
-import java.util.*;
+import org.jgrapht.Graph;
+import org.jgrapht.GraphTests;
+import org.jgrapht.Graphs;
+import org.jgrapht.util.CollectionUtil;
 
 /**
  * A lexicographical breadth-first iterator for an undirected graph.
@@ -162,7 +169,7 @@ private V advance()
      */
     private Set<V> getUnvisitedNeighbours(V vertex)
     {
-        Set<V> unmapped = new HashSet<>();
+        Set<V> unmapped = new LinkedHashSet<>();
         Set<E> edges = graph.edgesOf(vertex);
         for (E edge : edges) {
             V oppositeVertex = Graphs.getOppositeVertex(graph, edge, vertex);
@@ -311,7 +318,7 @@ private class Bucket
              */
             Bucket(Collection<V> vertices)
             {
-                this.vertices = new HashSet<>(vertices);
+                this.vertices = new LinkedHashSet<>(vertices);
             }
 
             /**
@@ -321,7 +328,7 @@ private class Bucket
              */
             Bucket(V vertex)
             {
-                this.vertices = new HashSet<>();
+                this.vertices = new LinkedHashSet<>();
                 vertices.add(vertex);
             }
 

diff --git a/jgrapht-core/src/test/java/org/jgrapht/traverse/DegeneracyOrderingIteratorTest.java b/jgrapht-core/src/test/java/org/jgrapht/traverse/DegeneracyOrderingIteratorTest.java
@@ -83,7 +83,7 @@ public void testGraph1()
             String v = it.next();
             sb.append("," + v);
         }
-        assertEquals(",v8,v6,v7,v5,v9,v10,v1,v2,v3,v4", sb.toString());
+        assertEquals(",v8,v6,v7,v5,v9,v10,v3,v4,v1,v2", sb.toString());
     }
 
     @Test
@@ -116,7 +116,7 @@ public void testGraphWithListener()
             it.next();
         }
         assertEquals(
-            ",s_a,f_a,s_b,f_b,s_d,f_d,s_c,f_c,s_j,f_j,s_i,f_i,s_k,f_k,s_e,f_e,s_f,f_f,s_g,f_g,s_h,f_h",
+            ",s_a,f_a,s_b,f_b,s_d,f_d,s_c,f_c,s_j,f_j,s_k,f_k,s_i,f_i,s_g,f_g,s_h,f_h,s_e,f_e,s_f,f_f",
             listener.toString());
     }