zh4ngx’s gists

zh4ngx / hill_climb_1

Created July 1, 2017 01:39

Basic Hill Climb with variance reduction for MC Policy Evaluation

	import gym
	import numpy as np
	from gym.wrappers.monitoring import Monitor

	env = gym.make('CartPole-v0')
	env = Monitor(env, 'tmp/cart-pole-hill-climb-1', force=True)

	print("Action space: {0}".format(env.action_space))
	print("Observation space: {0}\n\tLow: {1}\n\tHigh: {2}".format(
	env.observation_space,

zh4ngx / karabiner-import.sh

Created February 10, 2015 19:09

Quick settings for OS X Karabiner

	#!/bin/sh

	cli=/Applications/Karabiner.app/Contents/Library/bin/karabiner

	$cli set general.dont_remap_internal 1
	/bin/echo -n .
	$cli set remap.commandL2optionL 1
	/bin/echo -n .
	$cli set general.dont_remap_apple_pointing 1
	/bin/echo -n .

zh4ngx / interview_debug.py

Last active December 28, 2015 17:39

Simple interview question to test basic debugging & communication skills. May require a live person to answer questions (particularly if the candidate doesn't know Python). TODO: rewrite this in a few languages and put in a repo.

	def foo(a, b):
	"""Please document me.
	What am I supposed to do?
	Rename anything you see fit.
	Also, I think I have bugs. Please debug me.
	"""
	bar = {}
	for x in a:
	bar[x] = True

zh4ngx / lexical_closure.go

Created October 28, 2013 08:22

Quick demo/reminder of lexical closures (in Go)

	// You can edit this code!
	// Click here and start typing.
	package main

	import "fmt"

	func main() {
	fmt.Println("Hello, 世界")
	f := who()
	g := who()

zh4ngx / binary_tree_marshal.py

Created October 10, 2013 02:42

Function to marshal binary tree (represented as dict). Done kind of in a hurry (like 20m)....

	# Arbitary binary tree (integers)
	### 1
	### 2 3
	### 6 4 5
	## {1:{"left":2,"right":{3:{"left":4,"right":5}}}}
	## Goal: -> '{1:{left:2,right:{3:{left:4,right:5}}}}'

	# 1
	# 2 3
	## '{1:{left:2,right:3}}'

zh4ngx / sudoku.py

Created October 10, 2013 02:36

Quick solution to sudoku checker. Does NOT check if board is correctly completable, only if it's currently correct.

	# Check nums for rows, columns and blocks
	def check(nums):
	num_dict = {}
	# assume nums is a list of integers
	# placeholder for empty is None
	for num in nums:
	if not num:
	continue
	if num in num_dict:
	return false

zh4ngx / stack_machine_functional.rb

Created October 8, 2013 06:31

Functional-ish version of stack machine

	$stack = []

	def solution(s)
	s.each_char do \|c\|
	case c
	when /[0-9]/
	$stack.push c
	puts c
	when '+'
	return -1 unless op_nums(lambda { \|left, right\| left + right })

zh4ngx / simple_datastore.rb

Created October 2, 2013 07:59

Simple key-value datastore. Basic data & transaction commands.

	## SUMMARY
	# Use Hash($db) to maintain state
	# Track # open transactions
	# Memoize modified vars per transaction ($history)

	# Be naught, use globals (not thread-safe)
	$db = {}
	$transactions = 0
	$history = {}

zh4ngx / tokenize_string.rb

Created September 26, 2013 08:39

Given string and punctuation, tokenize string on punctuation and whitespace. Done using both split and scan.

	def tokenize_query_split query, punctuation
	punc_regex = /[#{punctuation}\s]+/

	tokens = query.split(punc_regex)

	tokens.each do \|token\|
	p token
	end
	end

zh4ngx / fizzbuzz.rb

Created September 26, 2013 08:10

Extensible FizzBuzz

	def fizzbuzz(max):
	1.upto(max).each do \|num\|
	line = ''
	line << 'Fizz' if num % 3 == 0
	line << 'Buzz' if num % 5 == 0
	line = num if line.empty?
	p line
	end
	end

Andy Zhang zh4ngx