moves-in-squared-strings-iii

Moves in squared strings (III)

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.

• Symmetry with respect to the main diagonal: diag_1_sym (or diag1Sym or diag-1-sym)

diag_1_sym(s) => "aeim\nbfjn\ncgko\ndhlp"

• Clockwise rotation 90 degrees: rot_90_clock (or rot90Clock or rot-90-clock)

rot_90_clock(s) => "miea\nnjfb\nokgc\nplhd"

• selfie_and_diag1(s) (or selfieAndDiag1 or selfie-and-diag1) It is initial string + string obtained by symmetry with respect to the main diagonal.

s = "abcd\nefgh\nijkl\nmnop" --> 
"abcd|aeim\nefgh|bfjn\nijkl|cgko\nmnop|dhlp"

or printed for the last:

selfie_and_diag1
abcd|aeim
efgh|bfjn
ijkl|cgko 
mnop|dhlp

Task

• Write these functions diag_1_sym, rot_90_clock, selfie_and_diag1

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 diag_1_sym, rot_90_clock, selfie_and_diag1)

Examples

s = "abcd\nefgh\nijkl\nmnop"
oper(diag_1_sym, s) => "aeim\nbfjn\ncgko\ndhlp"
oper(rot_90_clock, s) => "miea\nnjfb\nokgc\nplhd"
oper(selfie_and_diag1, s) => "abcd|aeim\nefgh|bfjn\nijkl|cgko\nmnop|dhlp"

Notes

• The form of the parameter fct in oper changes according to the language. You can see each form according to the language in "Your test cases".
• It could be easier to take these katas from number (I) to number (IV)
• Bash Note: The output strings should be separated by \r instead of \n. See "Sample Tests".

A forthcoming kata will study other transformations.