##2017 zero in: IV muscle build`

Zero-in on the highest leverage points.

There’s not enough focus compared to my UChicago days…

• [BP, ECT] coding practice in cpp/vi
• algo practice, in py or cpp. Follow online question banks. • [QQ] review my c++ blog, and read my books
• quant? no real target until I start interviewing
• data analytics? Nothing specific to study

%%c++IV weaker cf java#2017introspection

https://bintanvictor.wordpress.com/2017/04/02/c-and-java-iv-tend-to-beat-us-in-2-ways-high-end/ shows my self-rating in job interviews for c++ vs java. (For real projects, I think the gap between my c++ and java is slightly smaller.)

I did spend lots of time reading and blogging about c++, not less than java, so

Q: why the persistent gap in my QQ IV performance?

  • –A #1: I feel a disproportionate number of my c++ interviews come from high end teams, They go slightly more low-level than my java interviews. Imagine if I get more high end java interviews from the likes of Millennium, HSBC … I feel most (like 80%) of the java jobs in finance are “regular”; for c++, it’s more like 50%.
  • –A #3: significantly simpler — java as a language, when we ignore the add-on packages.
  • –A #2: a lot of the tough C++ IV questions are about
    • linux,
    • [C] sockets,
    • [C] *alloc function, memory leak detectors
    • [C] IPC
    • [C] other command line developer tools … mostly designed for the “system programmer”.
    • Some of these interviewers basically treat c++ as a wrapper over C. In contrast, Java insulates you in a pure-java world on the Virtual Machine, so you don’t need to deal with the messy “borders” as c# and c++ developers do.
  • –A: STL containers — is much more complicated than java containers in job interviews, even if we ignore iterators, stl algorithms. I spent more time studying STL than java collections but always failed to impress interviewers.
  • –A: halos — in my “java show” include threading, collections, GC tuning … which make up for my weaknesses. No such halo in my “c++ show” I guess some people have a halo in templates, memory mgmt, shared_ptr, threading…
  • –A: unable to describe c++ projects.
  • Suggestion: Start from this blog and my books. Focus on a small subset of core topics in c++, /burn through/ the essential literature and develop a first halo —
    1. smart pointers (beyond shared_ptr)
      1. usage in big5
      2. usage in containers
    2. data structures in STL and boost, including c-str life-cycle management excluding the str* functions
    3. traditional big 3(dtor,op=, copier) but not rvr and move-semantic
    4. pbclone^pbref but not return-value-optimization
    5. const
    6. vptr, slicing, dynamic_cast
  • (Note this is all about QQ book knowledge, not coding skill!)
  • suggestion: secondary focus topics —
    1. c++11 threading
    2. heap memory management;
    3. socket tweaking;
    4. interface classes, pure virtual;
  • suggestion: continue to ignore some of the high complexity low leverage topics such as move semantics; iterators; const-correctedness; singleton; design patterns; operator overload … and many [[effectiveC++]] topics

##10basic programming constructs4c++cod`IV

See EPI300

  1. std::string (more useful than cStr)
  2. vector (more useful than array) sorted data structure (i.e. stl map), unordered_map
  3. Node class used in a linked graph
  4. dtor, copier, op=
  5. ref only as function I/O
  6. iterator – basic usage
  7. double pointer
  8. stack, queue
  9. pointer arithmetic
  10. shared_ptr
  11. local static

no exception
stl algo? Only Citadel array-shrink
no pointer to function
no template
no (very, very seldom) threading in coding Q
adv: matrix
adv: circular buffer

 

c++GTD^IV muscle building: X years xp: U can cut by half

What specific topics to improve for c++ (not pure algo) coding IV? (X years experience doesn’t guarantee anything)

  • · Write code to print alternative item reversely
  • · Write ref-counted string
  • · Write auto-ptr

What specific topics to improve for c++ QnA IV? (X years experience doesn’t guarantee anything)

So in any of these areas, x years spent using a language could leave you still total beginner!

tough n high-leverage c++topics#IV QQ

I used to feel I have so much learning(absorption) capacity, but now I feel in my finite career I can’t really master and remember all the tough c++ topics.

Practical solution — Classify each difficult c++topic into one of

  1. QQ: high impact on QnA interview, probably the only type of high-leverage tough topic. Largely textbook knowledge. As such I’m basically confident I can learn all the basics on my own (perhaps slower than Venkat), provided I know the topics.
    1. including “coding questions” designed really for knowledge test, rather than algorithm thinking
    2. eg: HFT, Venkat…
  2. high impact on algo coding IV? No such topic. These coding IV are not about knowledge in tough topics!
  3. ZZ: high impact on GTD zbs — inevitably Low leverage during job hunt
  4. 00: no high impact on anything

Q: Is there a tough topic in both QQ and ZZ? I don’t know any.

I think 00 will be the biggest category:

  • [00] template wizardry;
  • [00] template specialization
  • [00] MI;
  • [00] operator overloading;
  • [00] pthread
  • ————-
  • [QQ]
  • [QQ] move semantics
  • [QQ] boost common lib
  • [QQ] optimization tricks. Remember MIAX and SCB IV by Dmitry
  • [QQ] singleton implementation — not really tough
  • [QQ] pimpl — not really tough
  • [QQ] op-new/malloc (interacting with ctor)
  • [QQ] memory layout
  • [QQ] specific threading constructs
  • [QQ] smart ptr details
  • [QQ] ptr as a field
  • [QQ] implement auto_ptr or ref-counting string
  • [QQ] UDP — not really tough
  • [QQ] select()
  • [QQ] multicast
  • [QQ]
  • [ZZ] IDE set-up
  • [ZZ] compiler/linker/makefile details
  • [ZZ] debuggers
  • [ZZ] crash analysis, like segmentation fault

 

2017%%c++IV=B- i.e 6 #java=8

Looking at my blog posts, I did accumulate quite a lot of valuable knowledge, some of them useful to projects, most of them important to QnA interviews.

I would venture to say that even a 5Y c++ veteran may not know these very well. The 4 categories are defined in https://bintanvictor.wordpress.com/2017/04/02/c-and-java-iv-tend-to-beat-us-in-2-ways-high-end/:

  • pseudo code algo? they would score LOWER than me
  • QQ (mostly theoretical)? they have NO advantage over me.
  • edit-compile-test type of short coding test? they would score higher than me
  • BP i.e. knowledge gap revealed in coding tests is my weakest? they would score B.

See https://bintanvictor.wordpress.com/2017/02/12/c-real-jobs-offers-i-got/