Initial commit

Medium/add-two-numbers/Solution.java

@@ -0,0 +1,44 @@
+class ListNode {
+    int val;
+    ListNode next;
+
+    ListNode() {
+    }
+
+    ListNode(int val) {
+        this.val = val;
+    }
+
+    ListNode(int val, ListNode next) {
+        this.val = val;
+        this.next = next;
+    }
+}
+
+class Solution {
+    public ListNode addTwoNumbers(ListNode list1, ListNode list2) {
+        ListNode head = new ListNode(0);
+        ListNode cur = head;
+
+        int carry = 0;
+        while (list1 != null || list2 != null) {
+            int dig1 = list1 != null ? list1.val : 0;
+            int dig2 = list2 != null ? list2.val : 0;
+
+            int sum = dig1 + dig2 + carry;
+            cur.next = new ListNode(sum % 10);
+            cur = cur.next;
+            carry = sum / 10;
+
+            if (list1 != null)
+                list1 = list1.next;
+            if (list2 != null)
+                list2 = list2.next;
+        }
+
+        if (carry > 0)
+            cur.next = new ListNode(carry);
+
+        return head.next;
+    }
+}