Semiperfect numbers
A semiperfect/pseudoperfect number is a number equal to the sum of a part or all of its divisor (excluding self).
Numbers which are equals to all of their divisors are perfect.
Divisors of 6 : 1,2,3
6 = 1+2+3 -> semiperfect (perfect)
Divisors of 28 : 1,2,4,7,14
...
Article Spinning with Spintax
Article spinning is a search engine optimization technique by which search engine optimizers post a unique version of relevant content on article directories, web 2.0 sites, or other sources for backlinks.
It is occasionally used by website authors on their own si...
A linear Diophantine equation in two variables is an equation of the form ax + by = c, where a, b and c are constant integers and x and y are integer variables.
For many naturally occurring Diophantine equations, x and y represent quantities that cannot be negative.
Task
Write a program or fun...
In schools across the world, children type a number into their LCD calculator, turn it upside down and erupt into laughter after creating the word 'Boobies'. Of course, this is the most popular word, but there are many other words which can be produced. All words must be less than 10 letters long...
For interactive questions, how much demand is there to be able to use a purely touchscreen device (no mouse, no physical keyboard). I'm asking thinking of Stack Snippets in questions. Are there any other places where being touch-enabled would make a difference?
I'm assuming tick boxes, radio but...
In typography, a counter is the area of a letter that is entirely or partially enclosed by a letter form or a symbol. A closed counter is a counter that is entirely enclosed by a letter form or symbol. You must write a program takes a string as input and prints the total number of closed counters...
I was recently reminded of the ??!??! operator in C. For fun, I came up with the following statement:
char * iDontEvenKnow = !1 ??!??! !0 ? "!???!?!??!?!?" : "??!?!??!??!?!?";
First of all, figure out what it does. Secondly, see if you can come up with your own obfuscation using ??!??!. You ca...
Write a "Hello, World!" program, in which the code works when the bytes are reversed in the opposite direction. If your code is multiline then the line order would also be reversed.
Additional rules:
Can't be the same backwards (or very similar)
Can't use comments
Can't be written in an esoter...
