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Ben Hoyt benhoyt

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benhoyt /
Last active May 20, 2018
Calculate the average number of moves in a snakes and ladders game
"""Calculate the average number of moves in a snakes and ladders game.
Because as a parent one gets roped into these board (boring?) games
every so often, and I wanted to calculate the average duration of a
snakes and ladders game. Turns out it's about 36 moves (though
admittedly that's for a single-player game). :-)
> python
Played 10000 rounds, averaged 36.0559 moves, max 324 moves, took 0.508s
benhoyt /
Created Nov 3, 2016
Test how many threads we can run at once
"""Test how many threads we can run at once."""
import itertools
import threading
import time
import sys
import requests
benhoyt / mandelbrot.go
Created Sep 21, 2018
Go program to print the Mandelbrot set on stdout
View mandelbrot.go
// Print the Mandelbrot set on stdout
package main
import (
const (
benhoyt / join.awk
Created Nov 20, 2018
AWK program to compare time complexity of joining strings
View join.awk
# AWK program to compare time complexity of joining strings using a
# simple O(N^2) algorithm and a slightly more complex O(N log N) one.
# Join array elements, separated by sep: O(N^2) version
function join1(a, sep, i, s) {
for (i = 1; i+1 in a; i++) {
s = s a[i] sep
if (i in a) {
s = s a[i]
benhoyt /
Created May 8, 2018
Calculate edit distance with simple (memoized) recursive algorithm
def distance(s, t, cache=None):
"""Return minimum edit distance between s and t, where an edit
is a character substitution, deletion, or addition.
if not s:
return len(t)
if not t:
return len(s)
if cache is None:
benhoyt /
Created Oct 17, 2019
Overview of (parts of) the Python standard library

I'm going to demo a bunch of Python builtin and stdlib functions. There's a lot to get through, so I'll be going fast, but please stop me and ask questions as we go. The goal is to give you a taste of Python's power and expressivity if you're not a Python person, or maybe teach you a few new tricks if you are already.

Built-in functions

# enumerate: iterate with index *and* item
>>> strings = ['123', '0', 'x']
>>> for i, s in enumerate(strings):
...     print(f'{i} - {s}')  # f-strings!
benhoyt /
Created Aug 3, 2016
An atomic, thread-safe incrementing counter for Python
"""An atomic, thread-safe incrementing counter."""
import threading
class AtomicCounter:
"""An atomic, thread-safe incrementing counter.
>>> counter = AtomicCounter()
>>> counter.increment()
benhoyt /
Created Aug 5, 2016
"Birthday problem" calculator in Python
"""Calculate the probability of generating a duplicate random number after
generating "n" random numbers in the range "d".
Usage: python n [d=365]
Each value can either be an integer directly, or in the format "2**x", where
x is the number of bits in the value.
For example, to calculate the probability that two people will have the same
birthday in a room with 23 people:
benhoyt / flattenjson.go
Created Jul 7, 2020
Little Go tool to flatten JSON input
View flattenjson.go
// Flatten JSON input
// Example:
// $ echo '{"user":"Ben","ints":[true,false,null],"sub":{"x":1,"y":2}}' | go run flattenjson.go
// _.ints[0] = true
// _.ints[1] = false
// _.ints[2] = null
// _.sub.x = 1
// _.sub.y = 2
benhoyt /
Created May 12, 2016
Print most frequent N-grams in given file
"""Print most frequent N-grams in given file.
Usage: python filename
Problem description: Build a tool which receives a corpus of text,
analyses it and reports the top 10 most frequent bigrams, trigrams,
four-grams (i.e. most frequently occurring two, three and four word
consecutive combinations).
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