Code Interview Yingcai Xiao - PowerPoint Presentation

Slide1

Code Interview

Yingcai

Xiao

Hari

Krishna

BodicharlaSlide2

Code Interview

What is it?

Books

The process

The questions

How to prepare?Slide3

What is it?

Code Interview: job interview involves designing and writing programs. (the contents relate to coding.)Slide4

Digital Interview

Digital Interview: online interview, video interview. The format relates to digital media. Can be real-time or pre-recorded. Slide5

Digital Interview

"The Essential Digital Interview Handbook"

by Paul J.

Bailo

online interview,

good reference even for face-to-face interview.Slide6

Books on Code Interview (in Safari)

"

Ace the Programming Interview: 160 Questions and Answers for Success

“

by

Edward

Guiness

"Programming Interviews Exposed: Secrets to Landing Your Next Job"

by

John

Mongan

; Eric

Giguere

; Noah Kindler

"Coding Interviews: Questions, Analysis & Solutions"

by Harry HeSlide7

Books on Code Interview (not in Safari)

"Cracking the Coding Interview: 150 Programming Interview Questions and Answers"

by

Gayle

Laakmann

McDowell

"Cracking the C, C++, and Java Interview"

by

S G

GaneshSlide8

The Process

Usually after HR screening interview

Or after a phone interview

Can be online (digital)

Or face-to-face

Usually one-on-one with your interviewer.

You may have something to write on. Slide9

The Process

You will be asked to write some code.

May need to talk through the question first

May be in an actual programming language

May be as pseudo-code. Slide10

The Questions

Compare two integers without using any comparison operators?Slide11

The Questions

Swap two integers without using a temp?Slide12

The Questions

Which one is faster?

int

I, J = 8;I = 0.5 * J;I = J / 2;I = J >> 1;Slide13

Array

Linked List

Array List

Hash Table Queue Stack Tree Graph

Data StructuresSlide14

Why different data structures?

Use minimum space (Array).

Fast to retrieve (Array).

Easy to search (Array, Indexing / Hashing, Tree). Easy to modify (Linked List). Persistent. (IDs not Pointers/References) Sharable over the Internet. (XML) Reduce coding errors. (Padded Array)

Data StructuresSlide15

Persistent. (IDs not Pointers/References)

There is no use to save pointers/references or transmit them over the Internet.

Serialization (memory automatically allocated during loading)

Use indexes to link data instead of pointers/references (indexed faceset)Data StructuresSlide16

Index Linked

Data StructureSlide17

Data

Structure for Graphics and VisualizationSlide18

Serialization of objectsSlide19

Serialization

Converting an object into a form that can be persisted or transported.

Save objects to permanent storages.Sent over the network. Pass on to another object.Slide20

Deserialization

Converts

a stream into an object. Together

, these processes allow data to be easily stored and transferred.Slide21

Requirements for Serialization

To allow an object to be serializable:

In a serializable class, you must ensure that

every instance variable of the class is also serializable.The class must be visible at the point of serialization.All primitive types are serializable.Slide22

Sample Code for Serialization

// serializable class

class SerializeEmployee

{public:  char character; unsigned int id;  // serializing method void Serialize(::std::ostream &os); //static deserializing method static SerializeEmployee Deserialize(::std::istream &is);};  

void

SerializeEmployee

::Serialize(

std

::

ostream

&

os

)

{

if (

os.good

())

{

os.write

((char*)&character,

sizeof

(character));

os.write

((char*)&id,

sizeof

(id));

}

}Slide23

Sample Code for Deserialization

SerializeEmployee

SerializeEmployee::

Deserialize(std::istream &is){ SerializeEmployee retval; if (is.good()) { is.read((char*)&retval.character, sizeof(retval.character)); is.read((char*)&retval.id, sizeof(retval.id)); } if (

is.fail

()) {

throw ::

std

::

runtime_error

("failed to read full

struct

");

}

return

retval

;

}Slide24

Serialization References

http://

en.wikipedia.org/wiki/Serialization

http://www.slideshare.net/imypraz/java-serialization-8916554?v=qf1&b=&from_search=8http://www.stackoverflow.com/questions/5707835/having-trouble-serializing-binary-data-using-ifstream-and-ofstreamSlide25

Sharable over the Internet. (XML)

Text based

User defined tags

No header InefficientData StructuresSlide26

Reduce coding errors. (Padded Array)

Bounds checker

Use padding cells at the beginning or end of an array.

Error if the padding cells were written to.Data StructuresSlide27

Space Partitioning

Quad Tree (for rectangular shapes)

Triangulation (for irregular shapes)

Data StructuresSlide28

Bubble

Merge

Quick

Heap InsertionSorting