(1)program sujet5

program sujet5;

uses wincrt;

var ch:string;

p,q:integer;

function verif(ch:string):boolean;

var i:integer;

test:boolean;

begin i:=0;

repeat i:=i+1;

if ch[i] in ['A'..'Z',' '] then test:=true else test:=false;

until (test=false ) or (i=length(ch)-1);

verif:=test;

end;

procedure saisie(var ch:string;var p,q:integer);

begin repeat

write('Donner une chaine ');

readln(ch);

until (verif(ch)) and (ch[length(ch)]='.');

repeat

write('p= '); readln(p);

write('q= '); readln(q);

until (p in [2..10]) and (q in [2..10]);

end;

function code(ch:string):string;

var i:integer;

chf:string;

begin chf:='';

for i:=1 to length(ch) do if ch[i] in ['A'..'Z'] then

chf:=chf+chr((p*(ord(ch[i])-64)+q) mod 26 +65) else

chf:=chf+ch[i];

code:=chf;

end;

begin

saisie(ch,p,q);

writeln(code(ch));

end.