ZJ2008树的统计（树链剖分）

type node1=record
     go,next:longint;end;
     node2=record
     l,r,mx,sum:longint;end;
var i,x,y,n,q,tmp,cnt,sz,code:longint;
    ch,st:string;
    fa:array[..,..] of longint;
    v,deep,son,head,pl,belong,vis:array[..] of longint;
    e:array[..] of node1;
    t:array[..] of node2;
procedure insert(x,y:longint);
 begin
 inc(cnt);e[cnt].go:=y;e[cnt].next:=head[x];head[x]:=cnt;
 inc(cnt);e[cnt].go:=x;e[cnt].next:=head[y];head[y]:=cnt;
 end;
procedure dfs1(x:longint);
 var i,j:longint;
 begin
 son[x]:=;vis[x]:=;
 for i:= to  do
  begin
  if deep[x]<(<<i) then break;
  fa[x,i]:=fa[fa[x,i-],i-];
  end;
 i:=head[x];
 while i<> do
  begin
  j:=e[i].go;
  if vis[j]= then
   begin
   deep[j]:=deep[x]+;
   fa[j,]:=x;
   dfs1(j);
   inc(son[x],son[j]);
   end;
  i:=e[i].next;
  end;
 end;
procedure dfs2(x,chain:longint);
 var i,j,k:longint;
 begin
 k:=;inc(sz);
 pl[x]:=sz;belong[x]:=chain;
 i:=head[x];
 while i<> do
  begin
  j:=e[i].go;
  if (deep[j]>deep[x]) and (son[j]>son[k]) then k:=j;
  i:=e[i].next;
  end;
 if k= then exit;
 dfs2(k,chain);
 i:=head[x];
 while i<> do
  begin
  j:=e[i].go;
  if (deep[j]>deep[x]) and (k<>j) then
   dfs2(j,j);
  i:=e[i].next;
  end;
 end;
function lca(x,y:longint):longint;
 var i,tmp:longint;
 begin
 if deep[x]<deep[y] then begin tmp:=x;x:=y;y:=tmp;end;
 tmp:=deep[x]-deep[y];
 for i:= to  do
  if (tmp and (<<i)<>) then x:=fa[x,i];
 for i:= downto  do
  if fa[x,i]<>fa[y,i] then
   begin
   x:=fa[x,i];y:=fa[y,i];
   end;
 if x=y then exit(x) else exit(fa[x,]);
 end;
procedure build(x,y,k:longint);
 var mid:longint;
 begin
 with t[k] do
  begin
  l:=x;r:=y;
  if l=r then exit;
  mid:=(l+r)>>;
  build(l,mid,k<<);
  build(mid+,r,k<<+);
  end;
 end;
 function max(x,y:longint):longint;
  begin
  if x>y then exit(x) else exit(y);
  end;
procedure change(x,y,k:longint);
 var mid:longint;
 begin
 with t[k] do
  begin
  if l=r then
   begin sum:=y;mx:=y;exit;end;
  mid:=(l+r)>>;
  if x<=mid then change(x,y,k<<)
  else change(x,y,k<<+);
  sum:=t[k<<].sum+t[k<<+].sum;
  mx:=max(t[k<<].mx,t[k<<+].mx);
  end;
 end;
function getsum(x,y,k:longint):longint;
 var mid:longint;
 begin
 with t[k] do
  begin
  if (l=x) and (r=y) then exit(sum);
  mid:=(l+r)>>;
  if x>mid then exit(getsum(x,y,k<<+))
  else if y<=mid then exit((getsum(x,y,k<<)))
  else exit(getsum(x,mid,k<<)+getsum(mid+,y,k<<+));
  end;
 end;
function getmx(x,y,k:longint):longint;
 var mid:longint;
 begin
 with t[k] do
  begin
  if (l=x) and (r=y) then exit(mx);
  mid:=(l+r)>>;
  if x>mid then exit(getmx(x,y,k<<+))
  else if y<=mid then exit(getmx(x,y,k<<))
  else exit(max(getmx(x,mid,k<<),getmx(mid+,y,k<<+)));
  end;
 end;
function solvesum(x,y:longint):longint;
 var sum:longint;
 begin
 sum:=;
 while belong[x]<>belong[y] do
  begin
  inc(sum,getsum(pl[belong[x]],pl[x],));
  x:=fa[belong[x],];
  end;
 inc(sum,getsum(pl[y],pl[x],));
 exit(sum);
 end;
function solvemx(x,y:longint):longint;
 var mx:longint;
 begin
 mx:=-maxlongint;
 while belong[x]<>belong[y] do
  begin
  mx:=max(mx,getmx(pl[belong[x]],pl[x],));
  x:=fa[belong[x],];
  end;
 mx:=max(mx,getmx(pl[y],pl[x],));
 exit(mx);
 end;
procedure init;
 begin
 readln(n);
 for i:= to n- do
  begin
  readln(x,y);insert(x,y);
  end;
 for i:= to n do read(v[i]);
 end;
procedure solve;
 begin
 build(,n,);
 for i:= to n do change(pl[i],v[i],);
 readln(q);
 for i:= to q do
  begin
  readln(st);
  ch:=copy(st,,pos(' ',st)-);
  delete(st,,pos(' ',st));
  val(copy(st,,pos(' ',st)-),x,code);
  delete(st,,pos(' ',st));
  val(st,y,code);
  case ch of
  'CHANGE':begin
           v[x]:=y;
           change(pl[x],y,);
           end;
  'QMAX':begin
         tmp:=lca(x,y);
         writeln(max(solvemx(x,tmp),solvemx(y,tmp)));
         end;
   else begin
         tmp:=lca(x,y);
         writeln(solvesum(x,tmp)+solvesum(y,tmp)-v[tmp]);
        end;
   end;
  end;
 end;
begin
 init;
 dfs1();
 dfs2(,);
 solve;
end.

作为以后的模版!