Substitution cipher: Difference between revisions
→{{header|Picat}}
Line 1,521:
This type of Encryption/Decryption scheme is often called a Substitution Cipher.</pre>
=={{header|Picat}}==
{{trans|Prolog}}
<lang Picat>main =>
S = "The quick brown fox jumped over the lazy dog",
cypher(S,E), % encrypt
println(E),
cypher(D, E), % decrypt
println(D),
S == D,
println(ok).
cypher(O, S) :-
nonvar(O),
var(S),
sub_chars(O,S).
cypher(O, S) :-
nonvar(S),
var(O),
sub_chars(O,S).
base("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ").
subs("VsciBjedgrzyHalvXZKtUPumGfIwJxqOCFRApnDhQWob LkESYMTN").
sub_chars(Original,Subbed) :-
base(Base),
subs(Subs),
maplist($sub_char(Base,Subs),Original,Subbed).
sub_char([Co|_],[Cs|_],Co,Cs) :- !.
sub_char([_|To],[_|Ts], Co, Cs) :- sub_char(To,Ts,Co,Cs).
maplist(Goal, List1, List2) :-
maplist_(List1, List2, Goal).
maplist_([], X, _) :- X = [].
maplist_([Elem1|Tail1],
[Elem2|Tail2],
Goal) :-
call(Goal, Elem1, Elem2),
maplist_(Tail1, Tail2, Goal).</lang>
{{out}}
<pre>tFqNokRJpNwbQShNOQYNAkDWqxNQEqbNLFqNnITMNxQC
The quick brown fox jumped over the lazy dog
ok</pre>
===Using maps===
<lang Picat>main =>
S = "The quick brown fox jumped over the lazy dog!!!",
E = encrypt(S),
println(E),
D = decrypt(E),
println(D),
D == S,
println(ok),
nl.
encrypt(L) = [EncryptMap.get(C,C) : C in L] =>
base(Base),
subs(Subs),
EncryptMap = new_map([B=S : {B,S} in zip(Base,Subs)]).
decrypt(L) = [DecryptMap.get(C,C) : C in L] =>
base(Base),
subs(Subs),
DecryptMap = new_map([S=B : {B,S} in zip(Base,Subs)]).
base("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz ").
subs("VsciBjedgrzyHalvXZKtUPumGfIwJxqOCFRApnDhQWob LkESYMTN").</lang>
{{out}}
<pre>tFqNokRJpNwbQShNOQYNAkDWqxNQEqbNLFqNnITMNxQC!!!
The quick brown fox jumped over the lazy dog!!!
ok</pre>
=={{header|PicoLisp}}==
| |||