Day 16 solution

Author: vamsikrish53

May LeetCoding Challenge/Day_ 16/Solution.java

@@ -1 +1,38 @@
+// https://leetcode.com/problems/odd-even-linked-list/
+/**
+ * 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 {
+ // Two pointer approach
+ public ListNode oddEvenList(ListNode head) {
+ if(head == null || head.next == null)
+ return head;
+ 
+ ListNode odd = head;
+ ListNode h_odd = head;
+ ListNode even = head.next;
+ ListNode h_even = head.next;
+ 
+ while(even != null) {
+ if(even.next == null) {
+ odd.next = h_even;
+ return h_odd;
+ }
+ odd.next = even.next;
+ odd = odd.next;
+ even.next = odd.next;
+ even= even.next;
+ }
+ odd.next = h_even;
+ 
+ return h_odd;
+ }
+}