# Odd Even Linked List

Category

Linked List

Checkbox

Checkbox

Difficulty

Medium

Index

30

Key Ideas

The key idea to solve the "Odd Even Linked List" problem is to separate the odd and even nodes into two separate linked lists, and then connect the last node of the odd list to the first node of the even list.

Problem Number

328

Problem Summary

LeetCode Problem 328, titled "Odd Even Linked List", is a medium difficulty problem in the Linked List category. The problem requires reordering a given linked list such that all nodes with odd indices appear before nodes with even indices. A key pitfall to watch out for is properly handling the connections between the nodes while rearranging them to maintain the correct order.

Solution Summary

The best solution for the Odd Even Linked List problem is to use two pointers,

`odd`

and `even`

, to keep track of the odd and even nodes respectively. We initialize `odd`

as the head of the linked list and `even`

as the head's next node. Then, we iterate through the linked list, connecting the odd nodes and even nodes separately. Finally, we connect the last odd node with the first even node to form the final result. This solution has a time complexity of O(N) and a space complexity of O(1), where N is the number of nodes in the linked list.Tags

Linked List