Add C++ code for the chapter binary tree.

codes/cpp/include/ListNode.hpp

@@ -25,7 +25,7 @@ struct ListNode {
  * @param list 
  * @return ListNode* 
  */
-ListNode* vectorToLinkedList(vector<int>& list) {
+ListNode* vecToLinkedList(vector<int> list) {
     ListNode *dum = new ListNode(0);
     ListNode *head = dum;
     for (int val : list) {

codes/cpp/include/PrintUtil.hpp

@@ -238,4 +238,27 @@ class PrintUtil {
             }
             cout << "[" + s.str() + "]" << '\n';
         }
+
+        /**
+         * @brief 
+         * 
+         * @tparam T 
+         * @param queue 
+         */
+        template <typename T>
+        static void printQueue(queue<T> &queue)
+        {
+            // Generate the string to print
+            ostringstream s;
+            bool flag = true;
+            while(!queue.empty()) {
+                if (flag) {
+                    s << queue.front();
+                    flag = false;
+                }
+                else s << ", " << queue.front();
+                queue.pop();
+            }
+            cout << "[" + s.str() + "]" << '\n';
+        }
 };

codes/cpp/include/TreeNode.hpp

@@ -23,7 +23,7 @@ struct TreeNode {
  * @param list 
  * @return TreeNode* 
  */
-TreeNode* vectorToTree(vector<int>& list) {
+TreeNode* vecToTree(vector<int> list) {
     TreeNode *root = new TreeNode(list[0]);
     queue<TreeNode*> que;
     que.emplace(root);