This is a very very simple algorithm, that I am sure can be solved in many many different languages. In Spain the ID cards (known as DNI) consist of 8 numbers and a control character. The control character is calculated with the following algorithm: divide the number by 23, take the rest of the o...

Inspired by the bugged output in @Carcigenicate's Clojure answer for the Print this diamond challenge. Print this exact text: 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 ...

// example from: // https://msdn.microsoft.com/en-us/library/windows/desktop/ms737591(v=vs.85).aspx #define WIN32_LEAN_AND_MEAN #include <windows.h> #include <winsock2.h> #include <ws2tcpip.h> #include <stdlib.h> #include <stdio.h> // Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib #p...

Write a program, that sends its own source code over network. Network example is TCP/UDP or web socket. Ethernet, bluetooth, Wi-Fi and internet over USB are allowed. No need to write reciver program. You can use any encoding protocol, but decoder will be realizable. Rules Network is not a st...

Code Golf - The Challenge: Write a function to reverse a string of text. For example, given: hello world it would return dlrow olleh You may not use a built in function to reverse the string.

BASKETBALL FRVR !!! You might already be familiar with the game: Basketball FRVR in facebook. Like in regular basketball, you can either hit a: 3 when the ball enters the basket without touching the rim (a virgin-shot: we call it so in our country :D) or 2 when the ball enters the basket but a...

Write a function that calculates a row of the pascal triangle and returns the middle number, if there are 2 it should return their sum. You may not use a built in function. Example: 5 would return 20 Example 2: 4 would return 6

Background Celebrating the release of Dyalog APL 16.0, where the solution to this problem is {⊢⌺(≢⍵)⊢⍵}. Task Given a printable ASCII string of odd length n, make an n × n square with the string centered horizontally, duplicated to be centered vertically, and with acrostics of the same string ...

What's Underneath the Sine Wave? kolmogorov-complexity code-golf Task Your task is to output a part of the sine wave out of any character of your choosing and on any background of your choosing (as long as the background is not any of the characters that are in the wave itself). The wave can s...

Given a positive integer as input, your task is to output a truthy value if the number is divisible by the double of the sum of its digits, and a falsy value otherwise. In other words: (sum_of_digits)*2 | number The values do not have to be constant, as long as the falsy values are clearly di...

Your mission Create, in the language of your choice, a program that outputs a randomly selected lennyface from a lennyface (artistic minifigures, see this) list. Rules Input : A list of lennyfaces and numbers. Output (STDOUT for example) : the randomly-selected lennyface. A line with a number...

Random lennyface selector Your mission Create, in the language of your choice, a program that outputs a randomly selected lennyface (artistic minifigures, see this) from a lennyface list. Rules Input : A list of lennyfaces and numbers. Output (STDOUT for example) : the randomly-selected lenn...