/algorithms

algorithms playground for common questions

Primary LanguageRuby

Algorithms

Algorithms playground for common questions solved in ruby syntax.
In case you want to prepare yourself for a job interview - try to solve it yourself first, then have a look here.

Why?

I interviewed with Google, Facebook, LinkedIn, Twitter and others. I also interviewed others myself. Sometimes it looks like they all ask you the same "out of the box" questions that don't really check knowledge but memorization of the same tricks. This is my way of saying - change your interview style. There are lots of smart people out there, this is not the best way to find them.

Problems

problem solution
Unique binary search trees click
House Robber click
Decode Ways click
Coin change click
Decode Strings click
Wiggle Subsequence click
Binary Tree Side View click
Unix path click
Array Product click
Top K Frequent Elements click
Sum 4 arrays click
Reverse Linked List click
Reverse String In-place click
Nested List Weight Sum II click
Symmetric Tree click
Dijkstra's shortest path between two nodes click
Kruskal's minimum spanning tree algorithm click
Find the square root of a number click
Add two binary numbers click
Binary search click
Longest increasing subsequence click
Find all permutations of array click
Finding all combinations of well-formed brackets click
Finding the powerset of a set click
Game of life click
Print all combinations of set joining click
count and say click
Telephone number to words click
Maximum contiguous subarray click
Max Stack click
Find the smallest biggest number that has the same digits click
Find the minimum insertions needed to make a word palindrome click
String matching - Knuth Morris Pratt algorithm KMP click
Balanced Parentheses click
Quicksort algorithm click
Mergesort algorithm click
Max Stocks Profit click
Countingsort algorithm click
Shellsort algorithm click
Knapsack problem click, click
Move Zeroes click
Longest common subsequence problem click , click
Monty Hall Problem click
Eucliden and Extended Eucliden algorithm click
Suggest index of a number in an array click
Range minimum query sparse table algorithm click
Insertion Sort click
Towers of Hanoi using Stack click
Tarjan's strongly connected components finder click

How?

Simply run ruby some_file.rb to execute the algorithm. At the bottom of each file there are some test samples.
example: ruby brackets_combinations.rb will print:
["((()))", "(()())", "(())()", "()(())", "()()()"].

Contribute

Did you find a bug? any way to do it better? please feel free to pull-request it :)