dbyr’s gists

dbyr / random_from_stream.rs

Last active July 15, 2020 08:39

I came up with an algorithm that provably selects a value at random in a completely balanced and fair manner from an iterator (applicable to streams too) of indeterminate length. I tried searching (admittedly briefly) for such an algorithm but didn't find anything, so I thought I'd publish this gist in case it's never been done before (which I d…

	use std::iter::Iterator;
	use rand; // requires the rand crate
	use rand::Rng;
	use std::f64;

	// I came up with this little algorithm because it seems
	// (as far as I could google) there are no simple methods
	// for selecting a single value randomly _and_ fairly
	// from a variable-size stream/iterator in a single pass.

dbyr / query.py

Last active April 30, 2025 23:03

A demonstration of a request to AWS's DynamoDB (in this case, a query) that does not use boto3. In benchmark tests this script outperforms boto3 in regards to time to complete a query.

	import sys, os, base64, datetime, hashlib, hmac
	import requests
	import json
	from typing import *

	# based on the example python code found here:
	# https://docs.aws.amazon.com/general/latest/gr/sigv4-signed-request-examples.html

	# call this method to query all items for a given primary hash key in a table
	# endpoint: the DynamoDB endpoint to query (for AWS servers, this is "https://dynamodb.{region}.amazonaws.com/")

dbyr / main.rs

Last active January 9, 2020 04:25

My first attempt at implementing a linked list in Rust. The basic structure is based off the linked list found in the "rust by example" instruction docs. I have added some extra methods to make the implementation more complete.

	mod linked_list {
	use std::fmt::Display;
	use std::default::Default;

	type Next<V> = Option<Box<Node<V>>>;

	struct Node<V> {
	val: V,
	next: Next<V>,
	}

dbyr / main.rs

Last active January 7, 2020 00:18

A first attempt by a beginner rustacean to create a generic sorting algorithm

	mod sort {
	fn insert_from_right<S>(vals: &mut [S], left: usize, right: usize) where S: Clone {
	let mut i = right;
	let mut temp;
	while i > left {
	temp = vals[i].clone();
	vals[i] = vals[i - 1].clone();
	vals[i - 1] = temp;
	i -= 1;
	}

dbyr / n2-vocab.txt

Created January 20, 2019 03:28

Anki study card import file (vocabulary up to N2). Import using '#' as the delimiting character. Compiled into anki-friendly format from https://jlptstudy.net/N2/?vocab-list

	あっ#あっ#Ah!, Oh!#int
	ああ#ああ#like that, that way#int
	愛#あい#love#n,n-suf,vs
	あいかわらず#あいかわらず#as ever, as usual, the same#adv,n
	挨拶#あいさつ#greeting, salutation#n,vs
	愛情#あいじょう#love, affection#n
	合図#あいず#sign, signal#n,vs
	アイスクリーム#アイスクリーム#ice cream#n
	愛する#あいする#to love#vs-s
	間#あいだ#space, room, time#n

dbyr / javatest.sh

Created January 5, 2019 00:42

Since university programming assignments often require "input/output" type of programming, I have made this simple script to run any number of input/output tests on a Java program.

	#!/bin/bash

	# this script will run input/output tests for java programs
	USAGE="Usage:

	javatest.sh <progpath> <inputs_folder_path> <expected_outputs_folder_path>

	The names of the input files is expected to be the same as the name of the corresponding expected output files."

	if [[ $# != 3 ]]; then

David B dbyr