MovesInSquaredStrings01.md

MovesInSquaredStrings01

This kata is the first of a sequence of four about "Squared Strings".

You are given a string of n lines, each substring being n characters long: For example:

s = "abcd\nefgh\nijkl\nmnop"

We will study some transformations of this square of strings.

Vertical mirror: vert_mirror (or vertMirror or vert-mirror)

vert_mirror(s) => "dcba\nhgfe\nlkji\nponm"

Horizontal mirror: hor_mirror (or horMirror or hor-mirror)

hor_mirror(s) => "mnop\nijkl\nefgh\nabcd"

or printed:

vertical mirror   |horizontal mirror
abcd --> dcba     |abcd --> mnop
efgh     hgfe     |efgh     ijkl
ijkl     lkji     |ijkl     efgh
mnop     ponm     |mnop     abcd

Task

Write these two functions

and

high-order function oper(fct, s) where

• fct is the function of one variable f to apply to the string s (fct will be one of vertMirror, horMirror)

Examples

s = "abcd\nefgh\nijkl\nmnop" oper(vert_mirror, s) => "dcba\nhgfe\nlkji\nponm" oper(hor_mirror, s) => "mnop\nijkl\nefgh\nabcd"

Note

The form of the parameter fct in oper changes according to the language. You can see each form according to the language in "Sample Tests".

Bash Note

The input strings are separated by , instead of \n. The output strings should be separated by \r instead of \n. See "Sample Tests".

Forthcoming katas will study other tranformations.