How is your Grammar?

[moose]

Here is my Python-solution:

Code: Select all

import re

#thanks to http://stackoverflow.com/questions/937697/can-you-pass-a-dictionary-when-replacing-strings-in-python
def dict_sub(d, text): 
  """ Replace in 'text' non-overlapping occurences of REs whose patterns are keys
  in dictionary 'd' by corresponding values (which must be constant strings: may
  have named backreferences but not numeric ones). The keys must not contain
  anonymous matching-groups.
  Returns the new string.""" 

  # Create a regular expression  from the dictionary keys
  regex = re.compile("|".join("(%s)" % k for k in d))
  # Facilitate lookup from group number to value
  lookup = dict((i+1, v) for i, v in enumerate(d.itervalues()))

  # For each match, find which group matched and expand its value
  return regex.sub(lambda mo: mo.expand(lookup[mo.lastindex]), text)


def replace(string):
    d={'A': 'is', 'B': 'mm', 'C': 'oo', 'D': 'rgr', 'E':'ryg', 'F': 'dth', 'G': 'you', 'H': 'esol', 'I': 'ionA', 'J':'GDaBarA', 'K':'veECFHutI','L':'PQ', 'M':'n','N':'m', 'O':'oaNcho', 'P':'MO', 'Q':'NR', 'R':'sky','S':'JKL'}
    return dict_sub(d, string)

string = 'S'
for i in xrange(0,20):
  print("%i: %s" %(i, string))
  string = replace(string)

[megabreit]

<insert_your_favorite_editor_here> search&replace

[bsguedes]

did it by head

[laz0r]

The syntax was practically valid Mathematica anyway

[lifthrasiir]

Simple solution:

Code: Select all

g = {
  'A': 'is',
  'B': 'mm',
  'C': 'oo',
  'D': 'rgr',
  'E': 'ryg',
  'F': 'dth',
  'G': 'you',
  'H': 'esol',
  'I': 'ionA',
  'J': 'GDaBarA',
  'K': 'veECFHutI',
  'L': 'PQ',
  'M': 'n',
  'N': 'm',
  'O': 'oaNcho',
  'P': 'MO',
  'Q': 'NR',
  'R': 'sky',
  'S': 'JKL',
}
a = 'S'; b = ''
while a != b:
  a, b = ''.join(g.get(c,c) for c in a), a
print a

[AMindForeverVoyaging]

Well, that one was easy.

[jonik555]

Fastest solution-> by head. just start from H and K (you see solution) and continue...

[Bliss]

paper and pen very easy

[muadiep]

Made a simple C# Programm for running this Grammar

Code: Select all

namespace How_is_your_grammer
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<string,string> dic = new Dictionary<string,string>();
            dic.Add("A","is");
            dic.Add("B","mm");
            dic.Add("C","oo");
            dic.Add("D","rgr");
            dic.Add("E","ryg");
            dic.Add("F","dth");
            dic.Add("G","you");
            dic.Add("H","esol");
            dic.Add("I","ionA");
            dic.Add("J","GDaBarA");
            dic.Add("K","veECFHutI");
            dic.Add("L","PQ");
            dic.Add("M","n");
            dic.Add("N","m");
            dic.Add("O","oaNcho");
            dic.Add("P","MO");
            dic.Add("Q","NR");
            dic.Add("R","sky");
            dic.Add("S", "JKL");
            
            int i = 0;
            string start = "JKL";
            string temp;
            while (i < 100)
            {
                temp = start;
                foreach (char s in start)
                {
                    string buchstabe = s.ToString();
                    string r = "";

                    if (dic.ContainsKey(buchstabe))
                    {
                        temp = temp.Replace(buchstabe, dic[buchstabe]);
                    }
                }
                start = temp;
                i++;
            }

            Console.WriteLine(start);
            Console.Read();
        }
    }
}

[ChrFriedel]

Did it without thinking

Code: Select all

Public Class Challenge

    Private msg As String = ""

    Public Sub Start()
        S()
        Debug.Print(msg)
    End Sub

    Public Sub AddLetters(letters As String)
        msg &= letters
    End Sub

    Public Sub A()
        AddLetters("is")
    End Sub

    Public Sub B()
        AddLetters("mm")
    End Sub

    Public Sub C()
        AddLetters("oo")
    End Sub

    Public Sub D()
        AddLetters("rgr")
    End Sub

    Public Sub E()
        AddLetters("ryg")
    End Sub

    Public Sub F()
        AddLetters("dth")
    End Sub

    Public Sub G()
        AddLetters("you")
    End Sub

    Public Sub H()
        AddLetters("esol")
    End Sub

    Public Sub I()
        AddLetters("ion")
        A()
    End Sub

    Public Sub J()
        G()
        D()
        AddLetters("a")
        B()
        AddLetters("ar")
        A()
    End Sub

    Public Sub K()
        AddLetters("ve")
        E()
        C()
        F()
        H()
        AddLetters("ut")
        I()
    End Sub

    Public Sub L()
        P()
        Q()
    End Sub

    Public Sub M()
        AddLetters("n")
    End Sub

    Public Sub N()
        AddLetters("m")
    End Sub

    Public Sub O()
        AddLetters("oa")
        N()
        AddLetters("cho")
    End Sub

    Public Sub P()
        M()
        O()
    End Sub

    Public Sub Q()
        N()
        R()
    End Sub

    Public Sub R()
        AddLetters("sky")
    End Sub

    Public Sub S()
        J()
        K()
        L()
    End Sub

End Class

[tiwe]

using sed:
$ cat grammar.sed
:a
s/A/is/g
...
s/S/JKL/g
t a
$ echo S | sed -f grammar.sed

[_matmat_]

Code: Select all

$value = "JKL";

while ($value =~ m/[A-Z]/) {
	$value =~ s/A/is/g;
	$value =~ s/B/mm/g;
	$value =~ s/C/oo/g;
	$value =~ s/D/rgr/g;
	$value =~ s/E/ryg/g;
	$value =~ s/F/dth/g;
	$value =~ s/G/you/g;
	$value =~ s/H/esol/g;		
	$value =~ s/I/ionA/g;	
	$value =~ s/J/GDaBarA/g;
	$value =~ s/K/veECFHutI/g;
	$value =~ s/L/PQ/g;
	$value =~ s/M/n/g;
	$value =~ s/N/m/g;				
	$value =~ s/O/oaNcho/g;				
	$value =~ s/P/MO/g;				
	$value =~ s/Q/NR/g;				
	$value =~ s/R/sky/g;								
	$value =~ s/S/JKL/g;				
}

print "val " . $value . "\n"

[kaio]

Should have been more steps to make it harder than simple pen&paper replacement.

[AMindForeverVoyaging]

You are free to submit a more complicated version of the same
That is, once you reach the "create a challenge" challenge.

[Limberneck]

Thisone reminded me of writing small compilers for expressions, very nice to do by hand.