2022-06-02 update: added "Count Complete Tree Nodes"

Author: fartem

src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/CountCompleteTreeNodes.java

@@ -0,0 +1,25 @@
+package com.smlnskgmail.jaman.leetcodejava.medium;
+
+import com.smlnskgmail.jaman.leetcodejava.support.TreeNode;
+
+// https://leetcode.com/problems/count-complete-tree-nodes/
+public class CountCompleteTreeNodes {
+
+    private final TreeNode input;
+
+    public CountCompleteTreeNodes(TreeNode input) {
+        this.input = input;
+    }
+
+    public int solution() {
+        return countNodes(input);
+    }
+
+    public int countNodes(TreeNode root) {
+        if (root == null) {
+            return 0;
+        }
+        return countNodes(root.left) + countNodes(root.right) + 1;
+    }
+
+}

src/test/java/com/smlnskgmail/jaman/leetcodejava/medium/CountCompleteTreeNodesTest.java

@@ -0,0 +1,32 @@
+package com.smlnskgmail.jaman.leetcodejava.medium;
+
+import com.smlnskgmail.jaman.leetcodejava.support.TreeNode;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class CountCompleteTreeNodesTest {
+
+    @Test
+    public void defaultTest() {
+        assertEquals(
+                6,
+                new CountCompleteTreeNodes(
+                        new TreeNode(
+                                1,
+                                new TreeNode(
+                                        2,
+                                        new TreeNode(4),
+                                        new TreeNode(5)
+                                ),
+                                new TreeNode(
+                                        3,
+                                        new TreeNode(6),
+                                        null
+                                )
+                        )
+                ).solution()
+        );
+    }
+
+}