bzoj2002 [Hnoi2010]Bounce 弹飞绵羊LCT

Posted 2020-08-20 ciao_sora

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=2002

第一道LCT，调了3天，发现是智障bug，我的青春。。。

主要参考了黄学长的代码，也没啥好说的，反正就是LCT，就当存一份模版好了。

#include <cstdio>

const int maxn = 200005;

int n, m, t1, t2, t3, ori_tree_fa[maxn];
int left[maxn], right[maxn], fa[maxn], siz[maxn], root;
int stk[maxn], top, pushdown_tem;
bool rev[maxn];

inline void pushup(int x) {
	siz[x] = siz[left[x]] + siz[right[x]] + 1;
}
inline void pushdown(int x) {
	if (rev[x]) {
		rev[x] = false;
		rev[left[x]] = !rev[left[x]];
		rev[right[x]] = !rev[right[x]];
		pushdown_tem = left[x];
		left[x] = right[x];
		right[x] = pushdown_tem;
	}
}
inline bool isroot(int x) {
	return left[fa[x]] != x && right[fa[x]] != x;
}
inline void leftrotate(int x) {
	int y = fa[x];
	if (!isroot(y)) {
		if (y == left[fa[y]]) {
			left[fa[y]] = x;
		}
		else {
			right[fa[y]] = x;
		}
	}
	fa[x] = fa[y];
	right[y] = left[x];
	fa[left[x]] = y;
	fa[y] = x;
	left[x] = y;
	pushup(y);
	pushup(x);
}
inline void rightrotate(int x) {
	int y = fa[x];
	if (!isroot(y)) {
		if (y == left[fa[y]]) {
			left[fa[y]] = x;
		}
		else {
			right[fa[y]] = x;
		}
	}
	fa[x] = fa[y];
	left[y] = right[x];
	fa[right[x]] = y;
	fa[y] = x;
	right[x] = y;
	pushup(y);
	pushup(x);
}
inline void splay(int x) {
	int p;
	top = 0;
	stk[top++] = x;
	for (int i = x; !isroot(i); i = fa[i]) {
		stk[top++] = fa[i];
	}
	for (int i = top - 1; i >= 0; --i) {
		pushdown(stk[i]);
	}
	while (!isroot(x)) {
		p = fa[x];
		if (isroot(p)) {
			if (x == right[p]) {
				leftrotate(x);
			}
			else {
				rightrotate(x);
			}
		}
		else {
			if (p == right[fa[p]]) {
				if (x == right[p]) {
					leftrotate(p);
					leftrotate(x);
				}
				else {
					rightrotate(x);
					leftrotate(x);
				}
			}
			else {
				if (x == right[p]) {
					leftrotate(x);
					rightrotate(x);
				}
				else {
					rightrotate(p);
					rightrotate(x);
				}
			}
		}
	}
}
inline void acc(int x) {
	int y = 0;
	while (x) {
		splay(x);
		right[x] = y;
		pushup(x);
		y = x;
		x = fa[x];
	}
}
inline void make_root(int x) {
	acc(x);
	splay(x);
	rev[x] = !rev[x];
}
inline void joyn(int x, int y) {
	make_root(x);
	fa[x] = y;
	splay(x);
}
inline void cutt(int x, int y) {
	make_root(x);
	acc(y);
	splay(y);
	left[y] = fa[x] = 0;
	pushup(y);
}

int main(void) {
	//freopen("in.txt", "r", stdin);
	scanf("%d", &n);
	root = n + 1;
	for (int i = 1; i <= n; ++i) {
		scanf("%d", &t2);
		t2 = i + t2 < root? i + t2: root;
		siz[i] = 1;
		fa[i] = ori_tree_fa[i] = t2;
	}
	siz[root] = 1;
	scanf("%d", &m);
	while (m--) {
		scanf("%d%d", &t1, &t2);
		++t2;
		if (t1 == 1) {
			make_root(root);
			acc(t2);
			splay(t2);
			printf("%d\n", siz[left[t2]]);
		}
		else {
			scanf("%d", &t3);
			t3 = t2 + t3 < root? t2 + t3: root;
			cutt(t2, ori_tree_fa[t2]);
			joyn(t2, t3);
			ori_tree_fa[t2] = t3;
		}
	}
	return 0;
}

　　我说的那个智障bug是指，splay开时前，pushdown那里，我错写成了

for (int i = x; !isroot(i); i = fa[i]) {
	stk[top++] = i;
}

　　被这个弄了好久。