fatherican
diff --git a/‎src/main/java/ssj/algorithm/SearchTree.java
Lines changed: 9 additions & 0 deletions b/‎src/main/java/ssj/algorithm/SearchTree.java
Lines changed: 9 additions & 0 deletions
diff --git a/‎src/main/java/ssj/algorithm/collections/AVLTree.java
Lines changed: 2 additions & 1 deletion b/‎src/main/java/ssj/algorithm/collections/AVLTree.java
Lines changed: 2 additions & 1 deletion
diff --git a/‎src/test/java/ssj/algorithm/collections/AVLTreeTest.java
Lines changed: 6 additions & 6 deletions b/‎src/test/java/ssj/algorithm/collections/AVLTreeTest.java
Lines changed: 6 additions & 6 deletions
@@ -1,5 +1,7 @@
 package ssj.algorithm;
 
+import com.google.common.base.Preconditions;
+
 import java.util.Iterator;
 
 /**
@@ -8,6 +10,13 @@
 public interface SearchTree<T extends Comparable<T>> extends Iterable<T> {
     void add(T ele);
 
+    default void addAll(Iterable<? extends T> iter) {
+        Preconditions.checkNotNull(iter);
+        for (T ele : iter) {
+            add(ele);
+        }
+    }
+
     int size();
 
     Iterator<T> preIterator();
 
@@ -203,7 +203,7 @@ private int pathLength(Node node) {
         return result;
     }
 
-    private Node getCommonNode(Stack<Node> one, Stack<Node> other) {
+    private Node getCommonNode(Stack<?extends Node> one, Stack<? extends Node> other) {
         Preconditions.checkNotNull(one);
         Preconditions.checkNotNull(other);
         Preconditions.checkArgument(!one.equals(other));
@@ -276,6 +276,7 @@ private Vector<LinkedList<Node>> createLevelLinkedList() {
      * @param tree
      * @return
      */
+    @SuppressWarnings("unused")
     public boolean isSubTree(AVLTree<T> tree) {
         Preconditions.checkNotNull(tree);
         if (_head.getValue() == null && tree._head.getValue() == null) {
 
@@ -176,22 +176,22 @@ public void testPathIterator() {
     public void testCommonParent() {
         int[] tree_data = new int[]{10, 4, 6, 14, 4, 8, 9, 12, 16, 11};
         AVLTree<Integer> tree = new AVLTree<>();
-        assertTrue(tree.commonParent(4, 8) == null);
+        assertTrue(tree.commonParent(8) == null);
         for (int i : tree_data) {
             tree.add(i);
         }
         //这个测试依赖于树的实现，并不通用
-        assertTrue(tree.commonParent(4, 8).equals(6));
-        assertTrue(tree.commonParent(9, 11).equals(10));
-        assertTrue(tree.commonParent(9, 4).equals(6));
-        assertTrue(tree.commonParent(16, 11).equals(14));
+        assertTrue(tree.commonParent(8).equals(6));
+        assertTrue(tree.commonParent(11).equals(10));
+        assertTrue(tree.commonParent(4).equals(6));
+        assertTrue(tree.commonParent(11).equals(14));
     }
 
     @Test
     public void testGetCommonParent() {
         int[] tree_data = new int[]{10, 4, 6, 14, 4, 8, 9, 12, 16, 11};
         AVLTree<Integer> tree = new AVLTree<>();
-        assertTrue(tree.commonParent(4, 8) == null);
+        assertTrue(tree.commonParent(8) == null);
         for (int i : tree_data) {
             tree.add(i);
         }