BZOJ2157【Link Cut Tree】

/* I will wait for you */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<algorithm>
#include<iostream>
#include<fstream>
#include<vector>
#include<queue>
#include<deque>
#include<set>
#include<map>
#include<string>

typedef long long LL;
typedef unsigned long long ULL;

using namespace std;

const int maxn=50010;
const int maxm=1010;
const int maxs=26;
const int INF=1<<29;
const int P=1000000007;
const double error=1e-9;

struct node
{
int key,sum,min,max,rev,set;
node *fa,*son[2];

int dir() { return this==fa->son[1]; }
int isroot() { return !fa||this!=fa->son[0]&&this!=fa->son[1]; }
}no[maxn];

inline void pushdown(node* o)
{
if(o->rev)
{
o->rev=0;swap(o->son[0],o->son[1]);
for(int i=0;i<2;i++) if(o->son[i]) o->son[i]->rev^=1;
}

if(o->set)
{
o->set=0;o->key=-o->key;o->sum=-o->sum;
swap(o->min,o->max);o->min=-o->min;o->max=-o->max;
for(int i=0;i<2;i++) if(o->son[i]) o->son[i]->set^=1;
}
}

inline void maintain(node* o)
{
if(o->key!=INF&&o->key!=-INF) o->sum=o->min=o->max=o->key;
else o->sum=0,o->min=INF,o->max=-INF;

for(int i=0;i<2;i++) if(o->son[i])
{
pushdown(o->son[i]);
o->son[i]->fa=o;
o->sum+=o->son[i]->sum;
o->max=max(o->max,o->son[i]->max);
o->min=min(o->min,o->son[i]->min);
}
}

inline void rotate(node* o)
{
node* p=o->fa;
pushdown(p);pushdown(o);
int d=o->dir();
p->son[d]=o->son[d^1];
o->son[d^1]=p;o->fa=p->fa;
if(!p->isroot()) p->fa->son[p->dir()]=o;
maintain(p);maintain(o);
}

inline void splay(node* o)
{
pushdown(o);
while(!o->isroot())
{
node* p=o->fa;
if(p->isroot()) rotate(o);
else if(o->dir()==p->dir()) rotate(p),rotate(o);
else rotate(o),rotate(o);
}
}

inline void access(node* o)
{
for(node* t=0;o;t=o,o=o->fa) splay(o),o->son[1]=t,maintain(o);
}

inline void evert(node* o)
{
access(o);splay(o);o->rev^=1;
}

inline void change(node* o,int k)
{
access(o);splay(o);o->key=k;maintain(o);
}

inline void qset(node* u,node* v)
{
evert(u);access(v);splay(v);v->set^=1;
}

inline void link(node* u,node* v)
{
evert(u);u->fa=v;
}

inline void qmax(node* u,node* v)
{
evert(u);access(v);splay(v);printf("%d\n",v->max);
}

inline void qmin(node* u,node* v)
{
evert(u);access(v);splay(v);printf("%d\n",v->min);
}

inline void qsum(node* u,node* v)
{
evert(u);access(v);splay(v);printf("%d\n",v->sum);
}

inline void make(node &o,int k)
{
o.key=o.sum=o.min=o.max=k;
o.rev=o.set=0;o.fa=o.son[0]=o.son[1]=0;
}

int main()
{
int n,cnt=0;scanf("%d",&n);
for(int i=0;i<n;i++) make(no[i],INF);

for(int i=1,u,v,w;i<n;i++)
{
scanf("%d%d%d",&u,&v,&w);make(no[n+i],w);
link(&no[n+i],&no[u]);link(&no[n+i],&no[v]);
}

int m,u,v;scanf("%d",&m);
while(m--)
{
char s[10];scanf("%s%d%d",s,&u,&v);
if(s[0]=='C') change(&no[n+u],v);
else if(s[0]=='N') qset(&no[u],&no[v]);
else if(s[0]=='S') qsum(&no[u],&no[v]);
else if(s[0]=='M'&&s[1]=='A') qmax(&no[u],&no[v]);
else if(s[0]=='M'&&s[1]=='I') qmin(&no[u],&no[v]);
}

return 0;
}