2. Add Two Numbers

algorithms/java/Add Two Numbers.java

@@ -0,0 +1,64 @@
+//Difficulty-Medium
+
+/**
+ * Definition for singly-linked list.
+ * public 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 l1, ListNode l2) {
+        int carry=0,sum=0,add=0;
+        ListNode head=new ListNode();
+        ListNode n=new ListNode(0,head);
+        while(l1!=null || l2!=null){
+            ListNode l3=new ListNode();
+            if(l1!=null && l2!=null){
+                add=l1.val+l2.val;
+                l1=l1.next;
+                l2=l2.next;
+            }
+            else if(l1!=null){
+                add=l1.val;
+                l1=l1.next;
+            }
+            else{
+                add=l2.val;
+                l2=l2.next;
+            }
+
+            sum=(add+carry)%10;
+            carry=(add+carry)/10;
+
+            if(head==null){
+                head.val=sum;
+                head.next=null;
+            }
+            else{
+                // n=head;
+                while(n.next!=null){
+                    n=n.next;
+                }
+                l3.val=sum;
+                l3.next=null;
+                n.next=l3;
+
+            }
+
+        }
+        if(carry==1){
+            ListNode node=new ListNode();
+            node.val=carry;
+            node.next=null;
+            while(n.next!=null)
+            n=n.next;
+            n.next=node;
+        }
+
+        return head.next;
+    }
+}