# Problem Definition

## Description

Sort a linked list using insertion sort.

We have explained Insertion Sort at Slide 7 of Arrays

[Insertion Sort Wiki](http://en.wikipedia.org/wiki/Insertion_sort#Algorithm) has some details on Insertion Sort as well.

Example :

Input : 1 -> 3 -> 2

Return 1 -> 2 -> 3

## Notes

1. [LeetCode discussion](https://discuss.leetcode.com/topic/8570/an-easy-and-clear-way-to-sort-o-1-space)