justinhj

#!/bin/bash
# A simple script to recursively search files

if [ "$#" -ne 3 ]; then
    echo "efind (easy find) usage: [path] [file pattern] [regex]"
    echo 'efind ../c "*.c" "string"'
    exit 1
fi

find "$1" -name "$2" -type f -print0 | xargs -0 egrep -iHn "$3"

justinhj

 // Determine if a value is the product of any two numbers in a vector
 // Converts the array to a stream so it can be consumed lazily
 // the helper function is recursive but subject to tail call optimization
 
 def prod(in: Array[Int], v: Int): Boolean = {
    def helper(in: Stream[Int], v: Int, found: Map[Int, Int]): Boolean = in match {
      case x #:: xs => {
      	val r = v / x
      	if(r * x != v) helper(xs, v, found)
      	else if(found.contains(x)) true

justinhj

	object FileExt {
		def unapply(s: String): Option[String] = {
			val parts: Array[String] = s.split('.')
			
			if(parts.length < 2) None
			
			else Some(parts.last)
		
		}
		

justinhj

# Copies a changelist (any files open for edit or add) to a directory you specify

# (C)2011 Justin Heyes-Jones

# TODO 
# Allow user to pass in PORT setting 
# Or at least check that it is set before doing perforce interactions
# P4 set P4PORT=servername:port 

import subprocess, sys, marshal, string, os, time, datetime

justinhj

State representation

In the 8Puzzle the state of each step in the solution is an array of tiles. In the water jug it can be an array of jug levels [0,0]

You can replace tiles with jugs TILE tiles[ BOARD_WIDTH*BOARD_HEIGHT ]; int jug_levels[ 2 ];

State transitions

justinhj

// Demonstrating futures running concurrently and in sequence

import scala.concurrent.{ExecutionContext, Future}
import scala.language.postfixOps

// A simple execution context for us to use that will not shut down the JVM until the threads we start have all finished
// It does that by making the threads non-Daemon

// http://stackoverflow.com/questions/25236143/why-future-example-do-not-work
// http://stackoverflow.com/questions/2213340/what-is-daemon-thread-in-java

justinhj

object Xmas1 {

  object Move {
    def fromString(arg: String): Option[Move] = arg match {

      case s if arg.startsWith("R") || arg.startsWith("L") =>
        try {

          val turn = if(arg.charAt(0) == 'R') Right else Left

justinhj

import scala.collection.{immutable, mutable}

object Xmas1 {

  object Move {
    def fromString(arg: String): Option[Move] = arg match {

      case s if arg.startsWith("R") || arg.startsWith("L") =>
        try {

justinhj

// Solution to http://adventofcode.com/2016/day/2

object Xmas2 {

  case class Transition(name: Char, target: Digit)

  case class Digit(value: Int, var transitions: Vector[Transition] = Vector[Transition]()) {
    def addTransitions(newTransitions: Vector[Transition]) = {
      transitions = transitions ++ newTransitions

justinhj

// Adapting part 1 to part 2 was a simple matter of changing the network of digits and transitions between them

object Xmas2 {

  case class Transition(name: Char, target: Digit)

  case class Digit(value: Int, var transitions: Vector[Transition] = Vector[Transition]()) {
    def addTransitions(newTransitions: Vector[Transition]) = {
      transitions = transitions ++ newTransitions