14
A tricky infinite sum
This challenge is write fast code that can perform a computationally difficult infinite sum.
Input
An n by n matrix P with integer entries that are smaller than 100 in absolute value. P will be symmetric and positive definite. You don't really need to know what that mean...
Introduction
Let a field be a rectangle filled with only the characters - and [0-9]. An example of a field is:
11-011123
111-010--
0010---01
111-01234
You see that this field has been separated into three smaller areas. To calculate the score of a smaller area, we just add all numbers up. For...
Stretch the word
The input is a word of lowercase letters not separated by whitespace. A newline at the end is optional.
The same word must be output in a modified version: For each character, double it the second time it appears in the original word, triple it the third time etc.
Example inpu...
4
This challenge is in honor of the Rookie of the Year category winners of Best of PPCG 2015: muddyfish (for I'm not the language you're looking for!) and quartata (for Implement a Truth-Machine).
Congratulations!
Background
In the deepest trenches of the ocean, there lives a rare and elusive squ...
What's being surrounded
I've always wanted to surround some text with #s, but I have trouble figuring out what I surrounded so in this challenge you'll be writing a program to do just that
Examples
Input / Outputs are separated by a newline.
###
#a#
###
a
#
#a#
#
a
###
# a #
...
