Add Two Numbers

include/s2_add_two_numbers.hpp

@@ -0,0 +1,31 @@
+#ifndef S2_ADD_TWO_NUMBERS_HPP
+#define S2_ADD_TWO_NUMBERS_HPP
+
+struct ListNode {
+  int val;
+  ListNode* next;
+  ListNode() : val(0), next(nullptr) {}
+  ListNode(int x) : val(x), next(nullptr) {}
+  ListNode(int x, ListNode* next) : val(x), next(next) {}
+};
+
+class Solution {
+ public:
+  /**
+   * @brief Add Two Numbers
+   *
+   * You are given two **non-empty** linked lists representing two non-negative
+   * integers. The digits are stored in **reverse order**, and each of their
+   * nodes contains a single digit. Add the two numbers and return the sum as a
+   * linked list.
+   *
+   * You may assume the two numbers do not contain any leading zero, except the
+   * number 0 itself.
+   *
+   * @param l1 the first linked list
+   * @param l2 the second linked list
+   */
+  ListNode* addTwoNumbers(ListNode* l1, ListNode* l2);
+};
+
+#endif