# bzoj 2049 [Sdoi2008]Cave 洞穴勘测 LCT

LCT模板题

### 代码

#include <bits/stdc++.h>
#define N 20010
using namespace std;
template <typename node> void chkmax(node &x, node y) {x = max(x, y);}
template <typename node> void chkmin(node &x, node y) {x = min(x, y);}
template <typename node> void read(node &x) {
x = 0; int f = 1; char c = getchar();
while (!isdigit(c)) {if (c == '-') f = -1; c = getchar();}
while (isdigit(c)) x = x * 10 + c - '0', c = getchar(); x *= f;
}
struct Node {
int fa, rev, pathfa, child[2];
} t[N];
int n, m;
int son(int x, int y) {return t[x].child[1] == y;}
void rev(int x) {t[x].rev ^= 1;}
void Clear() {
for (int i = 1; i <= n; i++)
t[i] = (Node) {0, false, 0, 0, 0};
}
void pushdown(int k) {
int x = t[k].rev;
if (x) {
swap(t[k].child[0], t[k].child[1]);
rev(t[k].child[0]), rev(t[k].child[1]);
t[k].rev = false;
}
}
void Connect(int x, int y, int k) {t[x].child[k] = y, t[y].fa = x;}
void Rotate(int x) {
int y = t[x].fa, z = t[y].fa; pushdown(y);
pushdown(x); int d = son(y, x);
swap(t[x].pathfa, t[y].pathfa);
Connect(z, x, son(z, y));
Connect(y, t[x].child[!d], d);
Connect(x, y, !d);
}
void Splay(int x) {
while (t[x].fa) {
int y = t[x].fa, z = t[y].fa;
if (z) {
pushdown(z), pushdown(y);
(son(z, y) ^ son(y, x)) ? Rotate(x) : Rotate(y);
}
Rotate(x);
}
}
void expose(int x) {
Splay(x); pushdown(x);
int y = t[x].child[1];
t[y].fa = 0, t[y].pathfa = x;
t[x].child[1] = 0;
}
void access(int x) {
for (expose(x); t[x].pathfa; Splay(x)) {
expose(t[x].pathfa);
Connect(t[x].pathfa, x, 1);
t[x].pathfa = 0;
}
}
void evert(int x) {access(x), Splay(x), rev(x);}
void link(int x, int y) {evert(y), t[y].pathfa = x;}
void cut(int x, int y) {
evert(x), access(y);
Splay(y); pushdown(y);
t[t[y].child[0]].fa = 0;
t[y].child[0] = 0;
}
int Find(int x) {
access(x);
for (pushdown(x); t[x].child[0]; x = t[x].child[0], pushdown(x));
return x;
}
int main() {
while (m--) {
char st[10];
scanf(" %s", st);
}