[URAL 1553]Caves and tunnels(树链剖分)

【题目大意】：

给你一棵最开始所有节点权值都为0的树，让你支持两种操作：

I A B表示在A号节点的权值上加上B。

G A B表示求A，B路径上最大的点权。

【题目分析】：

大题方向肯定没有问题还是树链剖分+线段树。

这题诡异再跳链上，因为跳链的过程当中LCA成为了一个很特殊的东西，最后我的解决方案就是干脆把他单拎出来处理掉。这题不开编译开关事不行了，否则会在第17个点爆栈。而且记得数组要开的够大！！

又因为这个卡了我15分钟…………吃饭之后才想到有可能是这个原因……

P.s.这个很无敌的编译开关（{$M 65536000} 无限系统栈……）

【代码】：

 {$M 65536000}program Project1;type ntype=record data,next,id:longint; end; ttype=record left,right,max:longint; end;var flag,v:array[0..100000] of boolean; chain,rank,links,num,locate,lcaans:array[0..100000] of longint; g,ques,setfather,max,father,size:array[0..100000] of longint; opr:array[0..100000,1..2] of longint; node,node2:array[0..400000] of ntype; tree:array[0..800000] of ttype; point,tot,top,q,n,m,i,x,y:longint; ch:char;function max2(x,y:longint):longint;begin if x>y then exit(x) else exit(y);end;procedure link(x,y:longint);begin inc(point); node[point].data:=y; node[point].next:=g[x]; g[x]:=point;end;procedure link2(x,y:longint);begin inc(point); node2[point].data:=y; node2[point].id:=q; node2[point].next:=ques[x]; ques[x]:=point;end;function findfa(x:longint):longint;begin if x=setfather[x] then exit(x); setfather[x]:=findfa(setfather[x]); exit(setfather[x]);end;procedure buildtree(p,left,right:longint);var mid:longint;begin tree[p].left:=left; tree[p].right:=right; if left=right then begin tree[p].max:=chain[left]; exit; end; mid:=(left+right) shr 1; buildtree(p shl 1,left,mid); buildtree(p shl 1+1,mid+1,right); tree[p].max:=max2(tree[p shl 1].max,tree[p shl 1+1].max);end;procedure insert(p,situ,delta:longint);var mid:longint;begin if tree[p].left=tree[p].right then begin tree[p].max:=tree[p].max+delta; exit; end; mid:=(tree[p].left+tree[p].right) shr 1; if situ<=mid then insert(p shl 1,situ,delta) else insert(p shl 1+1,situ,delta); tree[p].max:=max2(tree[p shl 1].max,tree[p shl 1+1].max);end;function find(p,left,right:longint):longint;var mid:longint;begin if (tree[p].left=left) and (tree[p].right=right) then exit(tree[p].max); mid:=(tree[p].left+tree[p].right) shr 1; if right<=mid then exit(find(p shl 1,left,right)) else if left>mid then exit(find(p shl 1+1,left,right)) else exit(max2(find(p shl 1,left,mid),find(p shl 1+1,mid+1,right)));end;procedure dfs(x:longint);var p:longint;begin max[x]:=0; size[x]:=1; v[x]:=true; p:=g[x]; while p<>0 do begin if not v[node[p].data] then begin father[node[p].data]:=x; dfs(node[p].data); inc(size[x],size[node[p].data]); if size[node[p].data]>size[max[x]] then max[x]:=node[p].data; end; p:=node[p].next; end;end;procedure cut(x:longint);var p:longint;begin v[x]:=true; inc(top); chain[top]:=0; locate[top]:=x; rank[x]:=top; if x=max[father[x]] then num[x]:=num[father[x]] else begin inc(tot); num[x]:=tot; links[tot]:=top; end; if max[x]<>0 then cut(max[x]); p:=g[x]; while p<>0 do begin if not v[node[p].data] then cut(node[p].data); p:=node[p].next; end;end;procedure lca(x:longint);var p:longint;begin setfather[x]:=x; p:=ques[x]; while p<>0 do begin if setfather[node2[p].data]<>0 then lcaans[node2[p].id]:=findfa(node2[p].data); p:=node2[p].next; end; p:=g[x]; while p<>0 do begin if setfather[node[p].data]=0 then begin lca(node[p].data); setfather[node[p].data]:=x; end; p:=node[p].next; end;end;procedure query(x,y:longint);var lca,ans:longint;begin lca:=lcaans[i]; ans:=-10000000; while x<>lca do if num[x]=num[lca] then begin ans:=max2(ans,find(1,rank[lca],rank[x])); break; end else if rank[x]=links[num[x]] then begin ans:=max2(ans,find(1,rank[x],rank[x])); x:=father[x]; end else begin ans:=max2(ans,find(1,links[num[x]],rank[x])); x:=locate[links[num[x]]]; end; ans:=max2(ans,find(1,rank[lca],rank[lca])); while y<>lca do if num[y]=num[lca] then begin ans:=max2(ans,find(1,rank[lca],rank[y])); break; end else if rank[y]=links[num[y]] then begin ans:=max2(ans,find(1,rank[y],rank[y])); y:=father[y]; end else begin ans:=max2(ans,find(1,links[num[y]],rank[y])); y:=locate[links[num[y]]]; end; writeln(ans);end;begin assign(input,'a.in'); assign(output,'a.out'); reset(input); rewrite(output); readln(n); point:=0; for i:=1 to n-1 do begin readln(x,y); link(x,y); link(y,x); end; dfs(1); fillchar(v,sizeof(v),0); cut(1); buildtree(1,1,top); point:=0; q:=0; readln(m); for i:=1 to m do begin read(ch); case ch of 'I':begin inc(q); readln(opr[q,1],opr[q,2]); end; 'G':begin readln(x,y); inc(q); opr[q,1]:=x; opr[q,2]:=y; flag[q]:=true; link2(x,y); link2(y,x); end; end; end; lca(1); for i:=1 to q do if flag[i] then query(opr[i,1],opr[i,2]) else insert(1,rank[opr[i,1]],opr[i,2]); close(input); close(output);end.