bzoj 1301 后缀数组

　　比较裸的后缀数组。

/**************************************************************
    Problem:
    User: BLADEVIL
    Language: Pascal
    Result: Accepted
    Time: ms
    Memory: kb
****************************************************************/

//By BLADEVIL
var
    s, str                  :array[..] of char;
    n, m, l                 :longint;
    i                       :longint;
    ws, wv                  :array[..] of longint;
    w                       :array[..,..] of longint;
    r, sa                   :array[..] of longint;

procedure da;
var
    i, j, p, k1, k2         :longint;
begin
    for i:= to m do ws[i]:=;
    for i:= to n do
    begin
        w[i][]:=r[i];
        inc(ws[r[i]]);
    end;
    for i:= to m do inc(ws[i],ws[i-]);
    for i:=n downto  do
    begin
        dec(ws[w[i][]]);
        sa[ws[w[i][]]]:=i;
    end;

    j:=; p:=;
    k1:=; k2:=;
    while p<=n do
    begin
        p:=; i:=n-j+;
        while i<=n do
        begin
            w[p][k2]:=i;
            inc(p);
            inc(i);
        end;
        for i:= to n do
            if sa[i]>=j then
            begin
                w[p][k2]:=sa[i]-j;
                inc(p);
            end;

        for i:= to n do wv[i]:=w[w[i][k2]][k1];
        for i:= to m do ws[i]:=;
        for i:= to n do inc(ws[wv[i]]);
        for i:= to m do inc(ws[i],ws[i-]);
        for i:=n downto  do
        begin
            dec(ws[wv[i]]);
            sa[ws[wv[i]]]:=w[i][k2];
        end;

        k1:=k1 xor ;
        k2:=k2 xor ;
        p:=;
        w[sa[]][k1]:=;
        for i:= to n do
        begin
            if (w[sa[i-]][k2]=w[sa[i]][k2]) and (w[sa[i-]+j][k2]=w[sa[i]+j][k2]) then
                w[sa[i]][k1]:=p- else
                begin
                    w[sa[i]][k1]:=p;
                    inc(p);
                end;
        end;
        j:=j<<; m:=p;
    end;

end;

begin
    n:=;
    while not eoln do
    begin
        read(str[n]);
        inc(n);
    end;
    l:=n; dec(n);
    s:=str;
    for i:=n+ to *n+ do s[i]:=str[i-n-];
    n:=*n+;
    s[n]:=chr();
    for i:= to n do
    begin
        r[i]:=ord(s[i]);
        if r[i]>m then m:=r[i];
    end;
    da;
    for i:= to n do
        if sa[i]<l then write(s[sa[i]+l-]);
    writeln;
end.