khmylov

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.

khmylov

let cleanText (lines: string[]) =
    lines
    |> Seq.skipWhile (fun str -> not (bookStarted str))
    |> Seq.takeWhile (fun str -> not (bookFinished str))
    |> String.concat " "
    |> Seq.map (fun c -> 
        if Char.IsLetter c then Char.ToLowerInvariant c
        else ' ')

// ---->        

khmylov

static void Profile(string description, int iterations, Action func) 
{
    // clean up
    GC.Collect();
    GC.WaitForPendingFinalizers();
    GC.Collect();

    // warm up 
    func();

khmylov

public class OverlappingAppBarBehavior: Behavior<PhoneApplicationPage>
{
    private static readonly double _appBarOffset = 74.0;
    private static readonly double _reducedAppBarOffset = 70.0;
    private static readonly double _appBarOpacity = 0.99;

    private static readonly IDictionary<PageOrientation, Thickness> _pageMargins = new Dictionary<PageOrientation, Thickness>
    {
        {PageOrientation.PortraitUp, new Thickness(0.0, 0.0, 0.0, _appBarOffset)},
        {PageOrientation.PortraitDown, new Thickness(0.0, _appBarOffset, 0.0, 0.0)},

khmylov

<phone:PhoneApplicationPage 
    x:Class="$namespace$.Page"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Style="{StaticResource DefaultPageStyle}"
    mc:Ignorable="d" 
    d:DesignHeight="800" 

khmylov

<Application 
    x:Class="$namespace$.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:system="clr-namespace:System;assembly=mscorlib"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone">

    <Application.Resources>
        <system:String x:Key="ApplicationTitle">APPLICATION TITLE</system:String>

khmylov

public static IObservable<TResult> SelectFromAsyncEventPattern
    <TSource, TResult, TDelegate, TEventArgs>(
    this IEnumerable<TSource> source,
    Action<TSource> run,
    Func<EventHandler<TEventArgs>, TDelegate> conversion,
    Action<TDelegate> subscribe,
    Action<TDelegate> unsubscribe,
    Func<TEventArgs, TResult> mapResult,
    Func<TEventArgs, Exception> mapException)

khmylov

public string GetExceptionLog(Exception exception)
{
    return UnwrapExceptionTextLoop(new StringBuilder(), 0, exception);
}

private string UnwrapExceptionTextLoop(StringBuilder sb, int level, Exception e)
{
    if (e == null)
    {
        return sb.ToString();

khmylov

public string GetAppVersion()
{
    var assembly = Assembly.GetExecutingAssembly();
    var name = assembly.FullName;
    var nameComponents = name.Split(',');

    if (nameComponents.Length >= 2)
    {
        var versionComponent = nameComponents[1];
        var keyAndValue = versionComponent.Split('=');

khmylov

public static IEnumerable<Tuple<T, T>> Pairwise<T>(this IEnumerable<T> source)
{
    if (source == null)
    {
        throw new ArgumentNullException("source");
    }

    var previous = default(T);

    using (var enumerator = source.GetEnumerator())