SPOJ913. Query on a tree II

题目大意：

询问一棵树上两点之间的边权和or第k个点是多少

link-cut tree

一开始把第k个点看成了第k大的边……吓了我一跳……

边权处理方法类似QTREE，再维护一个sum一个size就行了……

犯了脑残错误……调了半小时……

//Lib
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<ctime>

#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<queue>
using namespace std;
//Macro
#define rep(i,a,b) for(int i=a,tt=b;i<=tt;++i)
#define rrep(i,a,b) for(int i=a,tt=b;i>=tt;--i)
#define erep(i,e,x) for(int i=x;i;i=e[i].next)
#define irep(i,x) for(__typedef(x.begin()) i=x.begin();i!=x.end();i++)
#define read() (strtol(ipos,&ipos,10))
#define sqr(x) ((x)*(x))
#define pb push_back
#define PS system("pause");
typedef long long ll;
typedef pair<int,int> pii;
const int oo=~0U>>1;
const double inf=1e20;
const double eps=1e-6;
string name="",in=".in",out=".out";
//Var
struct T
{
	int LC,RC,FA,SIZE,KEY,SUM;
	void set(){LC=RC=FA=SIZE=KEY=SUM=0;}
	#define lc(x) tree[x].LC
	#define rc(x) tree[x].RC
	#define fa(x) tree[x].FA
	#define size(x) tree[x].SIZE
	#define key(x) tree[x].KEY
	#define sum(x) tree[x].SUM
}tree[10008];
struct E
{
	int node,next,v;
}e[20008];
int n,m,T;
int h[10008],tot;
void add(int a,int b,int c){e[++tot].next=h[a];e[tot].node=b;e[tot].v=c;h[a]=tot;}
void DFS(int x,int fa)
{
	int y;
	erep(i,e,h[x])if((y=e[i].node)!=fa)
	{
		key(y)=e[i].v;fa(y)=x;DFS(y,x);
	}
}
void Update(int x)
{
	sum(x)=sum(lc(x))+sum(rc(x))+key(x);
	size(x)=size(lc(x))+size(rc(x))+1;
}
void Zig(int x)
{
	int y=fa(x),z=fa(y);
	if(lc(z)==y)lc(z)=x;else if(rc(z)==y)rc(z)=x;fa(x)=z;
	fa(rc(x))=y;lc(y)=rc(x);rc(x)=y;fa(y)=x;
	Update(y);
}
void Zag(int x)
{
	int y=fa(x),z=fa(y);
	if(lc(z)==y)lc(z)=x;else if(rc(z)==y)rc(z)=x;fa(x)=z;
	fa(lc(x))=y;rc(y)=lc(x);lc(x)=y;fa(y)=x;
	Update(y);
}
bool isRoot(int x){return lc(fa(x))!=x&&rc(fa(x))!=x;}
void Splay(int x)
{
	for(int y,z;!isRoot(x);)
	{
		y=fa(x);z=fa(y);
		if(isRoot(y))
			if(lc(y)==x)Zig(x);
			else Zag(x);
		else
			if(lc(z)==y)
				if(lc(y)==x)Zig(y),Zig(x);
				else Zag(x),Zig(x);
			else
				if(rc(y)==x)Zag(y),Zag(x);
				else Zig(x),Zag(x);
	}
	Update(x);
}
void Expose(int x){for(int y=0;x;x=fa(x)){Splay(x);rc(x)=y;Update(x);y=x;}}
int Find(int root,int k)
{
	while(1)
	{
		if(size(lc(root))+1==k)return root;
		if(size(lc(root))>=k)root=lc(root);
		else{k-=size(lc(root))+1;root=rc(root);}
	}
}
int Query(int x,int y,int z=0)
{
	Expose(y);
	for(y=0;x;x=fa(x))
	{
		Splay(x);if(!fa(x))break;rc(x)=y;Update(x);y=x;
	}
	if(z==0)return sum(rc(x))+sum(y);
	if(size(y)>=z)return Find(y,size(y)-z+1);
	else if(size(y)+1==z)return x;
	else {z-=size(y)+1;return Find(rc(x),z);}
}
void Init()
{
	scanf("%d",&n);int a,b,c;
	rep(i,1,n)h[i]=0,tree[i].set();tot=1;
	rep(i,1,n-1)
	{
		scanf("%d%d%d",&a,&b,&c);
		add(a,b,c),add(b,a,c);
	}
	DFS(1,0);
}
void Work()
{
	int a,b,c;char ch[10];
	while(1)
	{
		scanf("%s",ch);
		if(ch[1]=='O')return;
		scanf("%d%d",&a,&b);
		if(ch[1]=='I')printf("%d\n",Query(a,b));
		else scanf("%d",&c),printf("%d\n",Query(a,b,c));
	}
}
int main()
{
//	freopen((name+in).c_str(),"r",stdin);
//	freopen((name+out).c_str(),"w",stdout);
	for(scanf("%d",&T);T;T--)
	{
		Init();
		Work();
	}
	return 0;
}