bzoj3489: A simple rmq problem （主席树）

{$inline on}
const
  maxn=200000;
  maxm=12000000;

var
  left,right,size,fix,max2,value:array[0..maxm]of longint;
  root,lson,rson,max:array[0..maxm]of longint;
  time,last,next,num:array[0..maxn]of longint;
  n,m,tot1,tot2,ll,rr:longint;
  flag:boolean;

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

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

procedure update(x:longint);inline;
begin
  max2[x]:=mmax(max2[left[x]],max2[right[x]]);
  if size[x]>0 then max2[x]:=mmax(max2[x],value[x]);
end;

procedure leftr(var x:longint);inline;
var
  k:longint;
begin
  k:=right[x];
  right[x]:=left[k];
  left[k]:=x;
  max2[k]:=max2[x];
  update(x);
  x:=k;
end;

procedure rightr(var x:longint);inline;
var
  k:longint;
begin
  k:=left[x];
  left[x]:=right[k];
  right[k]:=x;
  max2[k]:=max2[x];
  update(x);
  x:=k;
end;

procedure insert(var x:longint;y:longint);inline;
begin
  if x=0 then begin
    inc(tot2);
    x:=tot2;
    size[x]:=1;
    value[x]:=y;
    fix[x]:=random(maxn);
    max2[x]:=y;
    left[x]:=0;
    right[x]:=0;
    exit;
  end;
  if value[x]=y then begin
    if flag then inc(size[x])
      else dec(size[x]);
    update(x);
  end
  else
    if value[x]<y then begin
      insert(right[x],y);
      update(x);
      if fix[right[x]]>fix[x] then leftr(x);
    end
    else begin
      insert(left[x],y);
      update(x);
      if fix[left[x]]>fix[x] then rightr(x);
    end;
end;

procedure change(x,old,l,r,y:longint;var new:longint);inline;
var
  mid:longint;
begin
  inc(tot1);
  new:=tot1;
  if (ll<=l) and (r<=rr) then begin
    insert(root[x],y);
    max[new]:=max2[root[x]];
    lson[new]:=lson[old];
    rson[new]:=rson[old];
    exit;
  end;
  max[new]:=max2[root[x]];
  mid:=(l+r)>>1;
  if ll>mid then begin
    change(x<<1+1,rson[old],mid+1,r,y,rson[new]);
    lson[new]:=lson[old];
  end
  else
  if rr<=mid then begin
    change(x<<1,lson[old],l,mid,y,lson[new]);
    rson[new]:=rson[old];
  end
  else begin
    change(x<<1,lson[old],l,mid,y,lson[new]);
    change(x<<1+1,rson[old],mid+1,r,y,rson[new]);
  end;
end;

function query(x,l,r,y:longint):longint;inline;
var
  mid:longint;
begin
  //writeln(x);
  if l=r then exit(max[x]);
  mid:=(l+r)>>1;
  if y>mid then exit(mmax(max[x],query(rson[x],mid+1,r,y)))
    else exit(mmax(max[x],query(lson[x],l,mid,y)))
end;

procedure into;inline;
var
  i,j:longint;
begin
  readln(n,m);
  for i:=1 to n do read(num[i]);
  for i:=1 to n do last[i]:=n+1;
  for i:=n downto 1 do begin
    next[i]:=last[num[i]];
    last[num[i]]:=i;
  end;
  for i:=1 to n do
    if last[i]<>n+1 then begin
      ll:=last[i];
      rr:=next[ll]-1;
      flag:=true;
      change(1,time[1],1,n,i,time[1]);
    end;
  for i:=2 to n do begin
    ll:=i-1;
    rr:=next[i-1]-1;
    flag:=false;
    change(1,time[i-1],1,n,num[i-1],time[i]);
    if next[i-1]<>n+1 then begin
      ll:=next[i-1];
      rr:=next[ll]-1;
      flag:=true;
      change(1,time[i],1,n,num[i-1],time[i]);
    end;
  end;
end;

procedure work;inline;
var
  lastans,l,r:longint;
begin
  lastans:=0;
  while m>0 do begin
   // writeln(m,‘===========‘);
    dec(m);
    readln(l,r);
    l:=(l+lastans) mod n+1;
    r:=(r+lastans) mod n+1;
    if l>r then swap(l,r);
    lastans:=query(time[l],1,n,r);
    writeln(lastans);
  end;
end;

begin
  randomize;
  into;
  work;
end.