Add the initial EN translation for C++ code (#1346)

en/codes/cpp/utils/list_node.hpp

@@ -0,0 +1,42 @@
+/**
+ * File: list_node.hpp
+ * Created Time: 2021-12-19
+ * Author: krahets (krahets@163.com)
+ */
+
+#pragma once
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+/* Linked list node */
+struct ListNode {
+    int val;
+    ListNode *next;
+    ListNode(int x) : val(x), next(nullptr) {
+    }
+};
+
+/* Deserialize a list into a linked list */
+ListNode *vecToLinkedList(vector<int> list) {
+    ListNode *dum = new ListNode(0);
+    ListNode *head = dum;
+    for (int val : list) {
+        head->next = new ListNode(val);
+        head = head->next;
+    }
+    return dum->next;
+}
+
+/* Free memory allocated to the linked list */
+void freeMemoryLinkedList(ListNode *cur) {
+    // Free memory
+    ListNode *pre;
+    while (cur != nullptr) {
+        pre = cur;
+        cur = cur->next;
+        delete pre;
+    }
+}