Cover one more case for EquivalentNodesOfTree. Tired of it

Author: andrei-punko

src/main/java/by/andd3dfx/tree/equivalent/EquivalentNodesOfTree.java

@@ -7,7 +7,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.function.ToIntFunction;
 
 /**
  * <pre>
@@ -60,13 +59,17 @@ public List<Node> findEquivalentNodes(Node root) {
 
         return voc2NodesMap.values().stream()
                 .filter(nodes -> nodes.size() >= 2)
-                .min((o1, o2) -> o2.stream().mapToInt(nodeToIntFunction()).sum() - o1.stream().mapToInt(nodeToIntFunction()).sum())
-                .map(nodes -> nodes.subList(0, 2))
+                .map(nodes -> nodes.stream().sorted(this::compare).limit(2).toList())
+                .min(this::compare)
                 .orElse(null);
     }
 
-    private static ToIntFunction<Node> nodeToIntFunction() {
-        return node -> node.subtreeSize;
+    private int compare(Node n1, Node n2) {
+        return n2.subtreeSize - n1.subtreeSize;
+    }
+
+    private int compare(List<Node> list1, List<Node> list2) {
+        return list2.stream().mapToInt(node -> node.subtreeSize).sum() - list1.stream().mapToInt(node -> node.subtreeSize).sum();
     }
 
     private Set<Character> fillNodeVocabulary(Node node) {

src/test/java/by/andd3dfx/tree/equivalent/EquivalentNodesOfTreeTest.java

@@ -5,7 +5,6 @@
 
 import java.util.List;
 
-import static org.hamcrest.CoreMatchers.hasItem;
 import static org.hamcrest.CoreMatchers.hasItems;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.nullValue;
@@ -155,6 +154,8 @@ public void findEquivalentNodesAsymmetricCaseShouldChooseNodesWithMaxSubtreeSize
      *  D       E   D
      *             / \
      *            D   E
+     *           /
+     *          D
      * </pre>
      */
     @Test
@@ -172,11 +173,11 @@ public void findEquivalentNodesComplexCase() {
         root.right.right.right = new Node('D');
         root.right.right.right.left = new Node('D');
         root.right.right.right.right = new Node('E');
+        root.right.right.right.left.left = new Node('D');
 
         List<Node> result = equivalentNodesOfTree.findEquivalentNodes(root);
 
         assertThat("Two nodes expected", result.size(), is(2));
-        assertThat("Left node is absent", result, hasItem(root.left));
-        assertThat("Right node is absent", result, hasItem(root.right.right));
+        assertThat(result, hasItems(root.right.right, root.right.right.right));
     }
 }