What are some "classic" programming exercises?

sundialsvcs · 08-19-2013, 09:50 PM

Never mind "job interviews" .. or any such banal concerns.

The essential challenge that is posed by "any computing machine" is: how to make "a machine," despite its totally-silicon limitations, do something truly-useful for humans.

The limitations of digital computers have not changed since Von Neumann's time: they still consist of "1 and 0, with absolutely nothing in-between." The machinery still knows of nothing more than if..then..else. The gigabytes of (open source(!)) source-code that have been written since that time have not altered either the essential nature, or the essential challenge, of the problem.

Come with me, now, to what may seem to you to be "the dark ages." Surf to Amazon for the author James S Coan, and buy the titles, "Basic BASIC" and "Advanced BASIC." Circa 1976.

In those days, computers had advanced a full 30 years since Von Naumann's time, but (and I was there ... heh ...) had not yet advanced 40 years to the present day. Even so: "how things change... how things remain the same(!!)" (Electronic circuits are like that ...)

Grab these books, and solve the problems that they pose ... (without assistance!!) ... using the programming-languages and techniques of the present day. (After all, when these books were written, "BASIC" was "the programming-languages and techniques of the present day." And, guess what, 40 years from now ...)

"Welcome to our infatuation..."

danielbmartin · 08-21-2013, 09:18 PM

Quote:

Originally Posted by frieza

i remember a simple one from my programming class in college
create a program that outputs this

Code:

                  *
                 * *
                * * *
               * * * *
              * * * * *
             * * * * * *
            * * * * * * *
           * * * * * * * *

perhaps too simple?
make it so it takes input on how many rows tall

Improved awk to perform this task...

Code:

r=11  # r = number of rows in the output file
# cs = combined string
awk -v r=$r  \
 'BEGIN{for (j=1;j<=r;j++) cs=" " cs "* ";
        for (j=1;j<=r;j++) print substr(cs,j,j+r)}' >$OutFile

Daniel B. Martin

psionl0 · 08-21-2013, 10:48 PM

One interesting exercise is to get a "can't lose" betting system from the internet for roulette or baccarat and write a simulation that uses the system.

To allay fears that your program's PRN might not produce real results, download a file of random bytes from http://www.random.org/bytes/ and use those bytes to generate your random numbers.

OMouse · 08-22-2013, 07:20 PM

Your best bet are programming interview questions. They're full of classical problems, brain teasers and complex problems. Classical problems meaning string operations, linked list questions, graphing problems, etc. Brain teasers like how many fish can you put into a barrel before it's full. Complex problems meaning, how would you optimize the hell out of a web site and use caching, etc.

The two books that are solid are:

Some algorithms/data structures books include exercises too. I would recommend Sedgewick Algorithms, 4th Edition.

You can find more questions on Project Euler and Career Cup.

sycamorex · 08-23-2013, 08:14 PM

Quote:

Originally Posted by danielbmartin

Improved awk to perform this task...

Code:

r=11  # r = number of rows in the output file
# cs = combined string
awk -v r=$r  \
 'BEGIN{for (j=1;j<=r;j++) cs=" " cs "* ";
        for (j=1;j<=r;j++) print substr(cs,j,j+r)}' >$OutFile

Daniel B. Martin

And here's a python function that could do it. You can pass the number of rows to the function.

Code:

def tree(rows):
    for x in range(1, rows + 1):
        print(' ' * ((rows + 1) - x), ' *' * x)

YesItsMe · 07-09-2018, 09:19 AM

Everyone should have written at least one text editor once in his programming career.