vysakh0’s gists

vysakh0 / wercker.yml

Created July 14, 2016 11:36

	box: trenpixster/elixir:1.2.5

	services:
	- id: postgres
	env:
	POSTGRES_PASSWORD: postgres
	POSTGRES_USER: postgres

	build:
	steps:

vysakh0 / cookie.ex

Created June 30, 2016 09:17

To answer this reddit question https://www.reddit.com/r/elixir/comments/4qetef/pattern_matching_with_a_list_of_tuples/

vysakh0 / subarray_sum.ex

Last active June 29, 2016 14:51

Find if subarray with given sum exists

	defmodule SubarraySum do
	def run([], val), do: false
	def run([ _ \| rest ] = arr, val) do
	run(arr, val, 0) \|\| run(rest, val)
	end

	def run(_, val, val), do: true
	def run([], _val, _res), do: false
	def run(_, val, res) when(val < res), do: false

vysakh0 / cars_controller.ex

Last active March 7, 2016 16:39

Problem: Get cars from different vendors for a pickup and destination. Given each vendor has set prices for distances/places.

	# ...
	def index(conn, params) do
	model =
	Enum.map(vendor_ids, fn(vendor_id) ->
	Task.async(fn() ->
	Cabs.find_with_fare(params, vendor_id)
	# [ %Cab{price: 1, distance: 2},..]
	# Does some calculation based on results from different tables.
	end)
	end)

vysakh0 / hydra.ex

Last active February 19, 2016 14:04

The Process that retries itself without monitor, supervisors.

	defmodule Hydra do
	use GenServer

	def run(data) do
	{:ok, pid} = GenServer.start(__MODULE__, data, [])
	GenServer.cast(pid, :process)
	end

	def init(data) do
	{:ok, data}

vysakh0 / foo.ex

Created February 13, 2016 17:33

if the stream is "aaaafoo" and the word to search for is "foo", the function should print "Found foo" on the 6th incoming char (the last 'o' in "foo").

	defmodule Foo do
	def find(word) do
	find(IO.getn(""), word, word)
	end

	def find(_char, "", word) do
	IO.puts "Found #{word}"
	end

	def find(char, << char :: binary-size(1), rest :: binary >>, word) do

vysakh0 / prime.ex

Last active February 12, 2016 13:52

Find the list of prime numbers upto n

	defmodule Prime do
	def run(number) do
	max = :math.sqrt(number) \|> round
	result = Enum.to_list(2..number)
	run(max, result, {result, []})
	end
	def run(0, _, {res, sieve}) do
	Enum.reverse(sieve) ++ res
	end
	def run(max, [ head \| _ ], {result, sieve}) do

vysakh0 / frequent.ex

Last active February 11, 2016 05:17

Find the most frequent(continuously repeated) integer in a list.

	defmodule Frequent do
	def number( [num \| tail] ) do
	number({num, 1}, tail, {num, 1})
	end

	def number({num, count}, [ num \| tail ], max) do
	number({num, count + 1}, tail, max)
	end

	def number({_num, count} = current, [ diff \| tail ], {_, max_count} = max) do

vysakh0 / any.ex

Created February 10, 2016 03:49

Remove any given character in a string just using recursion

	defmodule Any do
	def remove(str, char) do
	remove("", str, char)
	end
	def remove(newstr, << char :: binary-size(1), rest :: binary >>, char) do
	remove(newstr, rest, char)
	end
	def remove(newstr, << first :: binary-size(1), rest :: binary >>, char) do
	remove(newstr <> first, rest, char)
	end

vysakh0 / palindrome.ex

Created February 9, 2016 04:04

A simple palindrome without using any inbuilt functions like `String.reverse` or `String.length`

	defmodule Palindrome do
	def check(<< first :: binary-size(1), rest :: binary >> = actual) do
	check(first, rest, actual)
	end

	def check(newstr, << next_letter :: binary-size(1), rest :: binary >>, actual) do
	check(next_letter <> newstr, rest, actual)
	end

	def check(reverse, <<>>, actual), do: reverse === actual

	defmodule Cookie do
	def run([ { "Set-Cookie", _} \| [{"Set-Cookie", val} \| _] ]), do: val
	def run([ _ \| rest ]), do: run(rest)
	end

Vysakh Sreenivasan vysakh0