OJ-Problems-Source/.ACM-Templates/Data-Structures/link-cut-tree/main.cpp

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2016-08-13 23:35:41 +08:00
const int MAXN = 100010;
struct Node {
Node *ch[2], *p; int size, value;
bool rev;
Node(int t = 0);
inline bool dir(void) {return p->ch[1] == this;}
inline void SetC(Node *x, bool d) {
ch[d] = x; x->p = this;
}
inline void Rev(void) {
swap(ch[0], ch[1]); rev ^= 1;
}
inline void Push(void) {
if (rev) {
ch[0]->Rev();
ch[1]->Rev();
rev = 0;
}
}
inline void Update(void) {
size = ch[0]->size + ch[1]->size + 1;
}
}Tnull, *null = &Tnull, *fim[MAXN];
// 要记得额外更新null的信息
Node::Node(int _value){ch[0] = ch[1] = p = null; rev = 0;}
inline bool isRoot(Node *x) {return x->p == null || (x != x->p->ch[0] && x != x->p->ch[1]);}
inline void rotate(Node *x) {
Node *p = x->p; bool d = x->dir();
p->Push(); x->Push();
if (!isRoot(p)) p->p->SetC(x, p->dir()); else x->p = p->p;
p->SetC(x->ch[!d], d);
x->SetC(p, !d);
p->Update();
}
inline void splay(Node *x) {
x->Push();
while (!isRoot(x)) {
if (isRoot(x->p)) rotate(x);
else {
if (x->dir() == x->p->dir()) {rotate(x->p); rotate(x);}
else {rotate(x); rotate(x);}
}
}
x->Update();
}
inline Node* Access(Node *x) {
Node *t = x, *q = null;
for (; x != null; x = x->p) {
splay(x); x->ch[1] = q; q = x;
}
splay(t); //info will be updated in the splay;
return q;
}
inline void Evert(Node *x) {
Access(x); x->Rev();
}
inline void link(Node *x, Node *y) {
Evert(x); x->p = y;
}
inline Node* getRoot(Node *x) {
Node *tmp = x;
Access(x);
while (tmp->Push(), tmp->ch[0] != null) tmp = tmp->ch[0];
splay(tmp);
return tmp;
}
// 一定要确定x和y之间有边
inline void cut(Node *x, Node *y) {
Access(x); splay(y);
if (y->p != x) swap(x, y);
Access(x); splay(y);
y->p = null;
}
inline Node* getPath(Node *x, Node *y) {
Evert(x); Access(y);
return y;
}
inline void clear(void) {
null->rev = 0; null->sie = 0; null->value = 0;
}