stephenLee

Inspired by this article. Neat tricks for speeding up integer computations.

Note: cin.sync_with_stdio(false); disables synchronous IO and gives you a performance boost. If used, you should only use cin for reading input (don't use both cin and scanf when sync is disabled, for example) or you will get unexpected results.

Multiply by a power of 2

x = x << 1; // x = x * 2

	import scala.collection.mutable.ArrayBuffer

	//Abstract class IntQueue
	abstract class IntQueue {
	def get(): Int
	def put(x: Int)
	}

	// A BasicIntQueue implemented with an ArrayBuffer
	class BasicIntQueue extends IntQueue {

	abstract class Expr
	case class Var(name: String) extends Expr
	case class Number(num: Double) extends Expr
	case class UnOp(operator: String, arg: Expr) extends Expr
	case class BinOp(operator: String, left: Expr, right: Expr) extends Expr

	val v = Var("x")
	val op = BinOp("+", Number(1), v)

	v.name

	val capitals = Map("France" -> "Paris", "Japan" -> "Tokyo")
	capitals get "France"
	capitals get "North Pole"

	def show(x: Option[String]) = x match {
	case Some(x) => x
	case None => "?"
	}

	show(capitals get "Japan")

	val capitals = Map("France" -> "Paris", "Japan" -> "Tokyo")
	capitals get "France"
	capitals get "North Pole"

	def show(x: Option[String]) = x match {
	case Some(x) => x
	case None => "?"
	}

	show(capitals get "Japan")

	#!/usr/bin/env python
	#coding=utf8
	import urllib
	import urllib2
	import cookielib
	import base64
	import re
	import json
	import hashlib
	import os

	# define variable, use using $()
	# -g add debug information to the executable file
	# -Wall turns on most, but not all, compiler warnings

	CC = g++
	CFLAGS = -g -Wall

	file: file.o
	$(CC) $(CFLAGS) -o file file.o
	file.o: file.cpp

	/*
	* Reference:
	* http://www.quora.com/Computer-Programming/What-are-some-cool-bit-manipulation-tricks-hacks
	* http://www.catonmat.net/blog/low-level-bit-hacks-you-absolutely-must-know/
	*/

	#include <iostream>
	#include <string.h>

	using namespace std;

	#!/usr/bin/env python
	# -- coding: utf-8 --

	import Queue

	"""

	Problem:(from http://weibo.com/lirenchen)

	从图左边入口处的2011进去，在迷宫里转悠，最后变成2012从右边出来。可以在迷宫里转圈，

	# define variable, use using $()
	# -g add debug information to the executable file
	# -Wall turns on most, but not all, compiler warnings
	# using Emacs and M-x replace-string RET string RET newstring RET
	# to replace xx to your file name.
	# Use google's testing framework
	GTEST_DIR = ../gtest

	# Where to find user code.
	USER_DIR = ../gtest_sample