rech dichotomique

program dichotomique ;
uses WinCrt;
type
    Tab = array [1..100] of integer;
var
    t : tab ;
    n : byte;
    k : integer;

Procedure inpn(var n : byte);
    begin
        Repeat
            ClrScr;
            Write('N= ');
                Readln(n);
        Until n in [5..10] ;
    end;

    Procedure fillT (var t : tab ; n : byte ) ;
        var
            a : integer;
        Begin
            for a:=1 to n do
             t[a]:=random(101);
        end;

        Procedure afft(t : tab ; n : byte );
            var
                a : Integer;
            Begin
                for a:=1 to n do
                  Write(t[a]:5);
                writeln;
            End;

            Procedure trins(var t : tab ; n : byte );
                var
                 a,b,stor : Integer;

                begin
                    a:=2 ;
                    while a<=n do
                        Begin
                            b:= a;
                         while (b>1 ) and (t[b-1] > t[b]) do
                            begin
                                stor:=t[b];
                                t[b]:=t[b-1];
                                t[b-1]:=stor;

                                b:=b-1;
                            end;
                            a:=a+1;
                        end;
                end;

                Function rech(t : tab ; n : byte ; k : integer):Boolean;
                    var
                        st,mid,en : Integer;    // start , middle , End
                    Begin
                        st:=1;
                        en:=n;
                        Repeat
                            mid := (st+en) div 2;
                            if k < t[mid] then
                                en:=mid-1
                            else
                                st:=mid+1;
                        until (k = t[st]) or (k = t[en]) or (k = t[mid]) or (en<st);
                        rech:= en>st;

                    end;

begin
    inpn(n);
    fillt(t,n);
    afft(t,n);
    trins(t,n);
    write('k= ');
     readln(k);
    writeln('Does ',k,' exist in T ? ',rech(t,n,k));
End.