reverse linked list iterative

fishercoder1534 · fishercoder1534 · commit ab11f6bea3cc · 2016-08-17T08:41:58.000-07:00
diff --git a/EASY/src/easy/ReverseLinkedList.java b/EASY/src/easy/ReverseLinkedList.java
@@ -0,0 +1,31 @@
+package easy;
+
+import utils.CommonUtils;
+import classes.ListNode;
+
+public class ReverseLinkedList {
+    //there's no reversion if the list is null or it contains only one node, so at a minimum, there should be 2 nodes
+    public ListNode reverseList(ListNode head) {
+        ListNode newHead = null;
+        while(head != null){
+            ListNode next = head.next;
+            head.next = newHead;
+            newHead = head;
+            head = next;
+        }
+        return newHead;
+    }
+
+    public static void main(String...strings){
+        ReverseLinkedList test = new ReverseLinkedList();
+        ListNode head = new ListNode(1);
+        head.next = new ListNode(2);
+        head.next.next = new ListNode(3);
+        head.next.next.next = new ListNode(4);
+        head.next.next.next.next = new ListNode(5);
+        CommonUtils.printList(head);
+        ListNode result = test.reverseList(head);
+        CommonUtils.printList(result);
+    }
+
+}
