grc-cohort-22#10 finished

Author: Elvin-code-dev

src/Practice.java

@@ -286,7 +286,20 @@ public static int nbSum(TreeNode<Integer> root) {
      * @return the count of nodes that do not have siblings, EXCLUDING THE ROOT
      */
     public static int onlyChildCount(TreeNode<?> root) {
-        return 0;
+        if (root == null) {
+            return 0;
+        }
+
+        int count = 0;
+
+        for (TreeNode<?> child : root.children) {
+            if (root.children.size() == 1) {
+                count++;
+            }
+            count += onlyChildCount(child);
+        }
+
+        return count;
     }
 
     /**