[deleted]

Procedure Prefix;
Var i,kk:longint;
Begin
  kk:=0;
  For i:=2 to n do
  Begin
    While (kk>0) and (a[kk+1]<>a[i]) do kk:=p[kk];
    If a[kk+1]=b[i] then inc(kk);
    p[i]:=kk;
  End;
End;

[deleted]

Thanks.

Edited by author 27.08.2006 12:38

your prefix function change 'b' whith 'a' and get AC

If a[kk+1]=b[i] then inc(kk) -> If a[kk+1]=a[i] then inc(kk)

Oh, thanks!
What a stupid mistake!
I must be more attentive!

Someone knows what is that test?
give me some tests please...

program stringtale;
var x,y:array[1..10000] of char;
n,i,s:integer;t:boolean;p:char;
  Begin
    readln(n);
    for i:=1 to n do read(x[i]);readln;
    for i:=1 to n do read(y[i]);s:=0;t:=false;
    while (not t) and (s<n) do
      Begin
        t:=true;
        for i:=1 to n do
          if x[i]<>y[i] then t:=false;
        s:=s+1;
        p:=x[n];
        for i:=n downto 2 do x[i]:=x[i-1];
        x[1]:=p;
      End;
    if t then write(s-1)
      else write('-1');
  End.

because your program not works for n>=32000(integer) but n maybe 250000. And x and y in your program very short - 10000, but maybe 250000