<p align="center">
  <img src="http://upload.wikimedia.org/wikipedia/commons/6/6a/Sorting_quicksort_anim.gif">
  <img src="http://upload.wikimedia.org/wikipedia/commons/c/cc/Merge-sort-example-300px.gif">
  <br/>
  <i>Wikipedia: Quicksort, Merge Sort</i>
</p>

algorithms-data-structures
============

Continually updated IPython Notebooks containing coding problems and solutions (algorithms and data structures).

Most solutions are in Python.

## Arrays and Strings

* [Determine if a string contains unique characters](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/arrays-strings/unique_chars.ipynb)
* [Reverse characters in a string](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/arrays-strings/reverse_string.ipynb)
* [Determine if a string is a permutation of another](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/arrays-strings/permutation.ipynb)
* [Encode spaces in a string in-place](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/arrays-strings/replace_char.ipynb)
* [Compress a string](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/arrays-strings/compress.ipynb)
* [Determine if a string is a rotation of another](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/arrays-strings/rotation.ipynb)

## Linked Lists

* [Implement a linked list with insert, find, delete, and print methods](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/linked-list.ipynb)
* [Remove duplicates from a linked list](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/remove-duplicates.ipynb)
* [Find the kth to last element of a linked list](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/kth-to-last-elem.ipynb)
* [Delete a node in the middle of a linked list, given access to only that node](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/delete-mid.ipynb)
* [Partition a linked list around a given value](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/partition.ipynb)
* [Add two numbers whose digits are stored in a linked list in reverse order](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/add-reverse.ipynb)
* [Find the start of a linked list loop](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/find-loop-start.ipynb)
* [Determine if a linked list is a palindrome](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/linked-lists/palindrome.ipynb)

## Stacks and Queues

* [Implement a stack with push, pop, and peek methods using a linked list](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/stack.ipynb)
* [Implement a queue with enqueue and dequeue methods using a linked list](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/queue.ipynb)
* [Implement n stacks using a single array](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/n-stacks.ipynb)
* [Implement a stack that keeps track of its minimum element](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/stack-min.ipynb)
* [Implement a set of stacks class that wraps a list of stacks, each bound by a capacity](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/set-of-stacks.ipynb)
* [Implement the Towers of Hanoi with 3 towers and N disks](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/hanoi.ipynb)
* [Implement a queue using two stacks](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/queue-from-stacks.ipynb)
* [Sort a stack using another stack as a buffer](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/stacks-queues/sort-stack.ipynb)

## Sorting and Searching

* [Implement selection sort](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/sorting-searching/selection-sort.ipynb#)
* [Implement insertion sort](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/sorting-searching/insertion-sort.ipynb#)
* [Implement quick sort](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/sorting-searching/quick-sort.ipynb#)
* [Implement merge sort](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/sorting-searching/merge-sort.ipynb#)

## Hacker Rank

* [Utopian Tree](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/hacker-rank/utopian-tree.ipynb)
* [Maximizing XOR](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/hacker-rank/maximizing-xor.ipynb)

## License

    Copyright 2015 Donne Martin

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
