Benjamin Baron benjbaron

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

Stores data elements based on an sequential, most commonly 0 based, index.
Based on tuples from set theory.

	#include <QtGui>
	#include <QGraphicsRectItem>
	#include <QGraphicsView>
	#include <QApplication>
	#include <QGraphicsSceneMouseEvent>

	class CustomItem : public QGraphicsEllipseItem
	{
	protected:
	void mousePressEvent(QGraphicsSceneMouseEvent *event)

	public static ArrayList<Map<String, String>> readCSV(String filePath) throws IOException {
	InputStream is = new FileInputStream(filePath);
	ArrayList<Map<String, String>> al = new ArrayList<Map<String, String>>();
	BufferedReader br = new BufferedReader(new InputStreamReader(is));
	String[] headerLine = br.readLine().split(","); // reads the header of the file
	String line = br.readLine(); // reads the first line of data
	while (line != null) {
	String[] values = line.split(",");
	Map<String, String> map = new HashMap<String, String>();
	for (int i = 0; i < values.length; i++) {

	class CSVParser
	{
	public:
	CSVParser() {}

	static int parseString(QString &buffer, QStringList &fields, QString delimChars, QString quoteChars, QString escapeChars) {
	QString field; // String in which to accumulate next field
	bool escaped = false; // Next char is escaped
	bool quoted = false; // In quotes
	QChar quoteChar = 0; // Actual quote character used to open quotes

	OGRLineString * convertFromGEOStoOGR(LineString * ls) {
	OGRLineString * lineString = (OGRLineString*) OGRGeometryFactory::createGeometry(wkbLineString);
	for(int i = 0; i < ls->getNumPoints(); ++i) {
	Point * pt = ls->getPointN(i);
	lineString->addPoint(pt->getX(), pt->getY());
	}
	return lineString;
	}

	QString checkFile(QString foldername, QStringList exts, QString filename) {
	foreach(auto ext, exts) {
	QFileInfo check(foldername+"/"+filename+"."+ext);
	if(check.exists() && check.isFile())
	return check.absoluteFilePath();
	return QString();
	}
	}

	// Use Gists to store code you would like to remember later on
	console.log(window); // log the "window" object to the console

	void OGRLayer::SetSpatialFilterRect( double dfMinX, double dfMinY,
	double dfMaxX, double dfMaxY )

	{
	OGRLinearRing oRing;
	OGRPolygon oPoly;

	oRing.addPoint( dfMinX, dfMinY );
	oRing.addPoint( dfMinX, dfMaxY );
	oRing.addPoint( dfMaxX, dfMaxY );

	import time
	from multiprocessing import Pool
	# can also work with ThreadPool, by importing
	# from multiprocessing.dummy import Pool


	def f1(a,b):
	print("run f1(%s,%s)" % (a,b))
	time.sleep(2)
	print("end f1")

	[github]
	user = benjbaron
	[push]
	default = current
	[pull]
	rebase = true
	[alias]
	st = status
	stp = status --porcelain
	ci = commit --amend --no-edit