Baccalauréat 2012 Sujet 4 Corrigé

Program S4 ; Var ch : string; //************************************** Function verif(ch:String) : boolean; Var ok : boolean; i : integer; Begin ok := true; i := 1; While (ok) And (i<=length(ch)) Do If (ch[i] In ['0'..'9']) Then i := i+1 Else ok := false; verif := ok; End; //************************************** Function EAN13(ch:String) : boolean; Var cc,v,e,s,r,i,p : integer; Begin val(ch[length(ch)],cc,e); s := 0; For i:=1 To length(ch)-1 Do Begin val(ch[i],v,e); If (i Mod 2=0) Then s := s+3*v Else s := s+v; End; r := s Mod 10; p := 10-r; EAN13 := (cc=p); End; //************************************** Begin Repeat write('Saisir un nombre de 13 chiffres: '); readln(ch); Until (length(ch)=13)And(verif(ch)); writeln; writeln('--------------------------------'); writeln; If (EAN13(ch)) Then writeln(ch,' est un code EAN13') Else writeln(ch,' n''est pas un code EAN13'); writeln; writeln('-------------------------------'); End.