jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

kerimdzhanov

/**
 * Get a random floating point number between `min` and `max`.
 * 
 * @param {number} min - min number
 * @param {number} max - max number
 * @return {number} a random floating point number
 */
function getRandomFloat(min, max) {
  return Math.random() * (max - min) + min;
}

kachayev

from collections import defaultdict
from heapq import *

def dijkstra(edges, f, t):
    g = defaultdict(list)
    for l,r,c in edges:
        g[l].append((c,r))

    q, seen, mins = [(0,f,())], set(), {f: 0}
    while q:

bearfrieze

Comprehensions in Python the Jedi way

by Bjørn Friese

Beautiful is better than ugly. Explicit is better than implicit.

-- The Zen of Python

I frequently deal with collections of things in the programs I write. Collections of droids, jedis, planets, lightsabers, starfighters, etc. When programming in Python, these collections of things are usually represented as lists, sets and dictionaries. Oftentimes, what I want to do with collections is to transform them in various ways. Comprehensions is a powerful syntax for doing just that. I use them extensively, and it's one of the things that keep me coming back to Python. Let me show you a few examples of the incredible usefulness of comprehensions.

econchick

class Graph:
  def __init__(self):
    self.nodes = set()
    self.edges = defaultdict(list)
    self.distances = {}

  def add_node(self, value):
    self.nodes.add(value)

  def add_edge(self, from_node, to_node, distance):

stefanbuck

#!/usr/bin/env bash
#
# Author: Stefan Buck
# License: MIT
# https://gist.github.com/stefanbuck/ce788fee19ab6eb0b4447a85fc99f447
#
#
# This script accepts the following parameters:
#
# * owner

benzittlau

 git ls-files | grep '\.swp$' | xargs git rm

clemensg

/* curl_multi_test.c

   Clemens Gruber, 2013
   <clemens.gruber@pqgruber.com>

   Code description:
    Requests 4 Web pages via the CURL multi interface
    and checks if the HTTP status code is 200.

   Update: Fixed! The check for !numfds was the problem.

pkerpedjiev

.

paul91

// All thanks goes to: http://stackoverflow.com/a/25733922

var ProtoBuf = require("protobufjs");
var http = require('http');

// MTA Realtime endpoint http://datamine.mta.info/mta_esi.php?key=xxxx
var feedUrl = "...";

// Initialize from .proto file
// Requires nyct-subway.proto and gtfs-realtime.proto