ex3_conv_bin_hex_bac_2010_principale

 program conv_bin_hex;
 uses wincrt;
 var
 ch:string;


function verif(ch:string):Boolean;
Var i:integer;
begin
        i:=1;
        while (ch[i] in ['1','0']) AND (i <= length(ch)) do
            i:=i+1;
        verif:= i > length(ch);
end;



procedure saisie(var ch:string);
begin
        repeat
            write('ch=');
            readln(ch);
        until (ch <> '') AND (verif(ch));
end;


function conv_10_b(x:integer;b:byte):string;
var R:integer;
ch,ch1:string;
begin
         ch:='';
         Repeat
                R:= X mod b;
                if R>= 10 then ch1:=ord(R+55)
                else str(R,ch1);
                ch:=ch1+ch;
                x:= x div b;
          until x = 0;
end;





function conv(ch:string):string;
Var
ch_hex,bloc:string;
i,x,e,bloc_dec:integer;
begin
            ch_hex:='';
            repeat
                i:=length(ch);
                bloc:='';
                Repeat
                            if length(ch) >= 4 then
                            begin
                                bloc:=ch[i] + bloc;
                                i:=i-1;
                            end
                            else
                            Repeat
                                ch:='0'+ ch;
                            until length(ch) = 4;
                until length(bloc) = 4;
                val(bloc,x,e);
                bloc_dec:=conv_bloc(x);
                ch_hex:= conv_10_b(x,15) + ch_hex;
                delete(ch,i,4);
            until ch='';
end;


begin
    saisie(ch);
    write('la conversion en hexadeciaml est : ',conv(ch));
end.