Golff y Côd - Treiglad

Question

Read this yng Nghymraeg

Challenge

Given a word in Welsh, output all of the possible mutated forms of the word.

Mutations

A mutation is a change of the first letter of a word when following certain words or in certain grammatical contexts.

In Welsh, the following are considered "consonants":

b c ch d dd f ff g ng h l ll m n p ph r rh s t th

Note that multiple character consonants such as ch, ng and rh are counted as one letter in Welsh, and therefore one consonant.

The other letters in the Welsh alphabet are vowels, listed below:

a e i o u w y

See below, all of the mutations with the original letter on the left and the resulting mutated letters on the right:

Original | Mutations
---------+---------------
p        | b mh ph
t        | d nh th
c        | g ngh ch
b        | f m
d        | dd n
g        | [no letter] ng
m        | f
ll       | l
rh       | r

Here, [no letter] means that the g is removed from the start of the word.

Note that there are some consonants which do not mutate:

ch
dd
f
ff
j
l
n
ng
ph
r
s
th

Vowels may also be found at the start of words but do not mutate:

a
e
i
o
u
w
y

Examples

Input: dydd

Output:

dydd
ddydd
nydd

---

Input: pobl

Output:

pobl
bobl
mhobl
phobl

---

Input: gwernymynydd

Output:

gwernymynydd
wernymynydd
ngwernymynydd

---

Input: ffrindiau

Output:

ffrindiau

---

Input: enw

Output:

enw

---

Input: theatr

Output:

theatr

---

_{On the request of ArtOfCode ;)}

Input: llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch

Output:

llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch
lanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch

Rules

The input will only ever be one word.

There will always be more letters after the leading consonant in your input.

Winning

The shortest code in bytes wins.

Answer 1

JavaScript (ES6), 180 bytes

x=>x.replace(/^([cpt](?!h)|d(?!d)|[bgm]|ll|rh)(.+)/,(_,y,z)=>({p:"b mh ph",t:"d nh th",c:"g ngh ch",b:"f m",d:"dd n",g:" ng",m:"f"}[y]||y[0]).split` `.map(b=>a.push(b+z)),a=[x])&&a

Outputs as an array of strings. This is my first try, so it's almost certainly not optimal.

Try it out

f=x=>x.replace(/^([cpt](?!h)|d(?!d)|[bgm]|ll|rh)(.+)/,(_,y,z)=>({p:"b mh ph",t:"d nh th",c:"g ngh ch",b:"f m",d:"dd n",g:" ng",m:"f"}[y]||y[0]).split` `.map(b=>a.push(b+z)),a=[x])&&a

<input id=A value="pobl"><button onclick="B.innerHTML=f(A.value).join('<br>')">Run</button><br>
<pre id=B>

Answer 2

C#, 356 338 360 bytes

I know that C# is a poor choice for code golf, but it's worth the shot:

Third attempt, all cases now pass, including th- ph- etc. This adjustment cost roughly 18 bytes.

Thanks pinkfloydx33 for the tips saving 24 bytes!

namespace System{using Linq;using S=String;class P{static void Main(S[]a){Action<S>w=Console.WriteLine;w(a[0]);foreach(S r in"th-dd-ch-ph-p.b.mh.ph-t.d.nh.th-c.g.ngh.ch-b.f.m-d.dd.n-g..ng-m.f-ll.l-rh.r".Split('-')){var b=r.Split('.');if(a[0].StartsWith(b[0])){foreach(S f in b.Skip(1))w(Text.RegularExpressions.Regex.Replace(a[0],$"^{b[0]}",f));break;}}}}}

Output

$> ./p gwernymynydd
gwernymynydd
wernymynydd
ngwernymynydd

Formatted Version

    namespace System {
    using Linq;
    using S = String;

    class P {
        static void Main(S[] a) {
            Action<S> w = Console.WriteLine;
            w(a[0]);
            foreach (S r in "th-dd-ch-ph-p.b.mh.ph-t.d.nh.th-c.g.ngh.ch-b.f.m-d.dd.n-g..ng-m.f-ll.l-rh.r"
                .Split('-')) {
                var b = r.Split('.');
                if (a[0].StartsWith(b[0])) {
                    foreach (S f in b.Skip(1))
                        w(Text.RegularExpressions.Regex.Replace(a[0], $"^{b[0]}", f));
                    break;
                }
            }
        }
    }
}

Answer 3

PowerShell v3+, 254 231 bytes

param($a)$a;$z=-join$a[1..$a.length]
if(($x=@{112='b mh ph';116='d nh th';99='g ngh ch';98='f m';100='dd n';109='f'})[+$a[0]]-and$a-notmatch'^[cpt]h|^dd'){-split$x[+$a[0]]|%{"$_$z"}}
($z,"ng$z")*($a[0]-eq103)
$z*($a-match'^ll|^rh')

working to golf further...

Examples

(Output is space-separated because that's the default Output Field Separator for stringified arrays. I don't know if the words I used for testing are actual words, but they fit the exceptions.)

PS C:\Tools\Scripts\golfing> 'dydd','pobl','gwernymynydd','ffrindiau','enw','rhee','llewyn','chern','ddydd','phobl'|%{"$_ --> "+(.\golff-yr-cod.ps1 $_)}
dydd --> dydd ddydd nydd
pobl --> pobl bobl mhobl phobl
gwernymynydd --> gwernymynydd wernymynydd ngwernymynydd
ffrindiau --> ffrindiau
enw --> enw
rhee --> rhee hee
llewyn --> llewyn lewyn
chern --> chern
ddydd --> ddydd
phobl --> phobl

Answer 4

Python 3, 196,189 185 bytes

Original attempt

w=input();print(w);[w.startswith(a)and[print(w.replace(a,i,1))for i in
r]+exit()for(a,*r)in(j.split(',')for j
in'th rh ph p,b,mh,ph t,d,nh,th c,g,ngh,ch b,f,m d,dd,n g,,ng m,f ll,l rh,r'.split())]

Vaultah noted that not w.find(a) would be a replacement for w.startswith(a) that would save 2 characters. But instead of not x and y we can use x or y which saves some characters more:

w=input();print(w);[w.find(a)or[print(w.replace(a,i,1))for i in
r]+exit()for(a,*r)in(j.split(',')for j
in'th rh ph p,b,mh,ph t,d,nh,th c,g,ngh,ch b,f,m d,dd,n g,,ng m,f ll,l rh,r'.split())]

Yet further savings by replacing w.replace(a,i,1) with i+w[len(a):]:

w=input();print(w);[w.find(a)or[print(i+w[len(a):])for i in
r]+exit()for(a,*r)in(j.split(',')for j
in'th rh ph p,b,mh,ph t,d,nh,th c,g,ngh,ch b,f,m d,dd,n g,,ng m,f ll,l rh,r'.split())]

Then I noticed that there was a bug, rh was listed twice; once in my short-circuit list that would take care of those double-letter consonants. Unfortunately dd was missing from there, so no savings, and we have

w=input();print(w);[w.find(a)or[print(i+w[len(a):])for i in
r]+exit()for(a,*r)in(j.split(',')for j
in'th ph dd p,b,mh,ph t,d,nh,th c,g,ngh,ch b,f,m d,dd,n g,,ng m,f ll,l rh,r'.split())]

Given any of the sample inputs, it gives the desired output; given

gorsaf

it outputs

gorsaf
orsaf
ngorsaf

and given input

theatr

it prints

theatr

Answer 5

C#, 349 bytes

Based on @grizzly's submission, but corrected to work with the consonants that don't get transformed (ph/ch/th/dd) that it wasn't working with, plus trimmed some excess out. Hope that's alright?

I had it down to 290 until I realized that I was missing the th/ch/ph/dd cases :-(. Adding in the Regex call killed it

namespace System{class P{static void Main(string[]a){var x=a[0];if(!Text.RegularExpressions.Regex.IsMatch(x,"^[pct]h|^dd"))foreach(var r in"p.b.mh.ph-t.d.nh.th-c.g.ngh.ch-b.f.m-d.dd.n-g..ng-m.f-ll.l-rh.r".Split('-')){var b=r.Split('.');if(a[0].StartsWith(b[0]))for(int i=1;i<b.Length;)x+='\n'+b[i++]+a[0].Substring(b[0].Length);}Console.Write(x);}}}

Interesting note, never knew that you could omit the space between var r in"string"

Formatted:

namespace System
{
    class P
    {
        static void Main(string[] a)
        {
            var x = a[0];
            if (!Text.RegularExpressions.Regex.IsMatch(x, "^[pct]h|^dd"))
                foreach (var r in"p.b.mh.ph-t.d.nh.th-c.g.ngh.ch-b.f.m-d.dd.n-g..ng-m.f-ll.l-rh.r".Split('-'))
                {
                    var b = r.Split('.');
                    if (a[0].StartsWith(b[0]))
                        for (int i = 1; i < b.Length;) x += '\n' + b[i++] + a[0].Substring(b[0].Length);
                }
            Console.Write(x);
        }
    }
}

Answer 6

Perl 6, 162 bytes

{/^(.|<[cprt]>h|dd|ff|ng|ll)(.*)/;(%('p',<b mh ph>,'t',<d nh th>,'c',<g ngh ch>,'b',<f m>,'d',<dd n>,'g',«'' ng»,'m',<f>,'ll',<l>,'rh',<r>){$0}//~$0).map(*~$1)}

Try it online!