#!ruby -nl pos = 0 out = "" while pos < 52 do current = $_[pos, 1] out = out + current before = pos > 0 ? $_[0 .. pos - 1] : "" after = pos < 51 ? $_[pos + 1 .. -1] : "" temp = before + "_" + after pos = temp.index(current) + 1 end puts out
Note that non-ascii characters in the above source code will be escaped (such as \x9f).