328. Odd Even Linked List

Author: zj

code/328. Odd Even Linked List/README.md

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+# 328. Odd Even Linked List
+Given a singly linked list, group all odd nodes together followed by the even nodes. Please note here we are talking about the node number and not the value in the nodes.
+
+You should try to do it in place. The program should run in O(1) space complexity and O(nodes) time complexity.
+
+##### Example:
+
+Given `1->2->3->4->5->NULL`,
+
+return `1->3->5->2->4->NULL`.
+
+##### Note:
+
+The relative order inside both the even and odd groups should remain as it was in the input. 
+
+The first node is considered odd, the second node even and so on ...

code/328. Odd Even Linked List/index.js

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+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+//Distribution 18.75%,runtime 162ms
+var oddEvenList = function(head) {
+    if(!head) return head;
+    var ohead = head.next;
+    var j = head;
+    var o = head.next;
+    var node = head.next;
+    while(node && node.next){
+        j.next = node.next;
+        o.next = node.next.next;
+        j = j.next;
+        o = o.next;
+        node = j.next;
+    }
+    j.next = ohead;
+    return head;
+};