【BZOJ1014】火星人prefix（splay，Hash）

题意：

、

思路：

 const mo=;
 var t:array[..,..]of longint;
     sum,size,fa,a,b,id,mi:array[..]of longint;
     n,m,i,x,y,s,k,j,cnt,root:longint;
     ch:ansistring;

 procedure swap(var x,y:longint);
 var t:longint;
 begin
  t:=x; x:=y; y:=t;
 end;

 procedure pushup(x:longint);
 var l,r:longint;
 begin
  l:=t[x,]; r:=t[x,];
  size[x]:=size[l]+size[r]+;
  sum[x]:=(sum[l]+int64(mi[size[l]])*b[x]+int64(mi[size[l]+])*sum[r]) mod mo;
  // sum[x]:=(sum[r]+int64(mi[size[r]])*b[x]+int64(mi[size[r]+])*sum[l]) mod mo; 也可以
 end;

 function min(x,y:longint):longint;
 begin
  if x<y then exit(x);
  exit(y);
 end;

 procedure rotate(x:longint;var k:longint);
 var y,z,l,r:longint;
 begin
  y:=fa[x]; z:=fa[y];
  if t[y,]=x then l:=
   else l:=;
  r:=l xor ;
  if y<>k then
  begin
   if t[z,]=y then t[z,]:=x
    else t[z,]:=x;
  end
   else k:=x;
  fa[x]:=z; fa[y]:=x; fa[t[x,r]]:=y;
  t[y,l]:=t[x,r]; t[x,r]:=y;
  pushup(y);
  pushup(x);
 end;

 procedure splay(x:longint;var k:longint);
 var y,z:longint;
 begin
  while x<>k do
  begin
   y:=fa[x]; z:=fa[y];
   if y<>k then
   begin
    if (t[y,]=x)xor(t[z,]=y) then rotate(x,k)
     else rotate(y,k);
   end
    else k:=x;
   rotate(x,k);
  end;
 end;

 procedure build(l,r,x:longint);
 var mid,now,last:longint;
 begin
  if l>r then exit;
  now:=id[l]; last:=id[x];
  if l=r then
  begin
   sum[now]:=a[now]; b[now]:=a[now];
   fa[now]:=last; size[now]:=;
   if l<x then t[last,]:=now
    else t[last,]:=now;
   exit;
  end;
  mid:=(l+r)>>; now:=id[mid];
  build(l,mid-,mid);
  build(mid+,r,mid);
  b[now]:=a[mid]; fa[now]:=last;
  pushup(now);
  if mid<x then t[last,]:=now
   else t[last,]:=now;
 end;

 function kth(x:longint):longint;
 var k,tmp:longint;
 begin
  k:=root;
  while k<> do
  begin
   tmp:=size[t[k,]]+;
   if tmp=x then exit(k);
   if tmp>x then k:=t[k,]
    else
    begin
     x:=x-tmp;
     k:=t[k,];
    end;
  end;
 end;

 function query(k,tot:longint):longint;
 var x,y:longint;
 begin
  x:=kth(k); y:=kth(k+tot+);
  splay(x,root);
  splay(y,t[x,]);
  exit(sum[t[y,]]);
 end;

 function ask(x,y:longint):longint;
 var l,r,mid,last:longint;
 begin
  l:=; r:=min(cnt-x,cnt-y)-; last:=;
  while l<=r do
  begin
   mid:=(l+r)>>;
   if query(x,mid)=query(y,mid) then begin last:=mid; l:=mid+; end
    else r:=mid-;
  end;
  exit(last);
 end;

 procedure ins(x,y:longint);
 var p,q,z:longint;
 begin
  p:=kth(x+);
  q:=kth(x+);
  splay(p,root);
  splay(q,t[p,]);
  inc(cnt); z:=cnt; t[q,]:=z;
  fa[z]:=q; b[z]:=y;
  pushup(z);
  pushup(q);
  pushup(p);
 end;

 begin

  readln(ch);
  n:=length(ch);
  for i:= to n+ do a[i]:=ord(ch[i-])-ord('a')+;
  mi[]:=;
  for i:= to  do mi[i]:=mi[i-]* mod mo;
  for i:= to n+ do id[i]:=i;
  build(,n+,); root:=(n+)>>; cnt:=n+;
  readln(m);
  for i:= to m do
  begin
   readln(ch); k:=length(ch); s:=; x:=; y:=;
   for j:= to k do
   begin
    if ch[j]=' ' then begin inc(s); continue; end;
    if s= then x:=x*+ord(ch[j])-ord('');
    if s= then y:=y*+ord(ch[j])-ord('');
   end;
   if ch[]='Q' then writeln(ask(x,y));
   if ch[]='R' then
   begin
    y:=y+ord('')-ord('a')+;
    k:=kth(x+); splay(k,root);
    b[k]:=y; pushup(root);
   end;
   if ch[]='I' then
   begin
    y:=y+ord('')-ord('a')+;
    ins(x,y);
   end;
  end;

 end.