CHAIN2 - Chuỗi từ

Tác giả: flashmt

Ngôn ngữ: Pascal

const fi='';
      fo='';
      maxn=250250;
type ar=array[1..maxn] of ansistring;
var n,re:longint;
    a:ar;
    f,d:array[0..maxn] of longint;

procedure rf;
var i:longint;
begin
     assign(input,fi);
     reset(input);
     readln(n);
     for i:=1 to n do readln(a[i]);
     close(input);
end;

procedure sort(l,r:longint);
var i,j:longint; x,y:ansistring;
begin
     i:=l; j:=r; x:=a[(i+j) div 2];
     repeat
           while a[i]<x do i:=i+1;
           while a[j]>x do j:=j-1;
           if i<=j then
           begin
                y:=a[i]; a[i]:=a[j]; a[j]:=y;
                i:=i+1; j:=j-1;
           end;
     until i>j;
     if i<r then sort(i,r);
     if l<j then sort(l,j);
end;

procedure pr;
var i,j,l:longint;
begin
     sort(1,n);
     for i:=2 to n do
     begin
          for j:=i-1 downto 1 do
          begin
               if a[i][1]<>a[j][1] then break;
               if pos(a[j],a[i])=1 then
               begin
                    d[i]:=j; break;
               end;
          end;
     end;
     f[1]:=1; re:=1;
     for i:=2 to n do
     begin
          f[i]:=f[d[i]]+1;
          if f[i]>re then re:=f[i];
     end;
end;

procedure wf;
begin
     assign(output,fo);
     rewrite(output);
     write(re);
     close(output);
end;

begin
     rf;
     pr;
     wf;
end.

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