_bzoj3223 Tyvj 1729 文艺平衡树【Splay】

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=3223

裸的，打个标记。

#include <cstdio>
#include <algorithm>

const int maxn = 100005;

int n, m, stk[maxn], top, t1, t2;
int fa[maxn], ch[maxn][2], root, siz[maxn];
char rev[maxn];

inline void pushdown(int x) {
	if (rev[x]) {
		rev[x] = 0;
		rev[ch[x][0]] ^= 1;
		rev[ch[x][1]] ^= 1;
		std::swap(ch[x][0], ch[x][1]);
	}
}
inline void pushup(int x) {
	siz[x] = siz[ch[x][0]] + siz[ch[x][1]] + 1;
}
inline void rotate(int x) {
	int y = fa[x];
	if (y == ch[fa[y]][0]) {
		ch[fa[y]][0] = x;
	}
	else {
		ch[fa[y]][1] = x;
	}
	fa[x] = fa[y];
	int dir = x == ch[y][1];
	ch[y][dir] = ch[x][dir ^ 1];
	fa[ch[x][dir ^ 1]] = y;
	ch[x][dir ^ 1] = y;
	fa[y] = x;
	pushup(y);
	pushup(x);
}
inline void splay(int x, int rt) {
	int p;
	top = 0;
	for (int i = x; i != rt; i = fa[i]) {
		stk[top++] = i;
	}
	for (int i = top - 1; ~i; --i) {
		pushdown(stk[i]);
	}
	while (fa[x] != rt) {
		p = fa[x];
		if (fa[p] == rt) {
			rotate(x);
		}
		else {
			if ((p == ch[fa[p]][1]) ^ (x == ch[p][1])) {
				rotate(x);
			}
			else {
				rotate(p);
			}
			rotate(x);
		}
	}
	if (!rt) {
		root = x;
	}
}
inline int kth(int k) {
	int x = root;
	pushdown(x);
	while (k != siz[ch[x][0]] + 1) {
		if (k <= siz[ch[x][0]]) {
			x = ch[x][0];
		}
		else {
			k -= siz[ch[x][0]] + 1;
			x = ch[x][1];
		}
		pushdown(x);
	}
	return x;
}
int make_tree(int left, int right) {
	if (left > right) {
		return 0;
	}
	int rt = (left + right) >> 1;
	ch[rt][0] = make_tree(left, rt - 1);
	fa[ch[rt][0]] = rt;
	ch[rt][1] = make_tree(rt + 1, right);
	fa[ch[rt][1]] = rt;
	pushup(rt);
	return rt;
}
void print(int r) {
	if (!r) {
		return;
	}
	pushdown(r);
	print(ch[r][0]);
	if (r != 1 && r != n + 2) {
		printf("%d ", r - 1);
	}
	print(ch[r][1]);
}

int main(void) {
	//freopen("in.txt", "r", stdin);
	scanf("%d%d", &n, &m);
	root = make_tree(1, n + 2);
	while (m--) {
		scanf("%d%d", &t1, &t2);
		++t1;
		++t2;
		t1 = kth(t1 - 1);
		t2 = kth(t2 + 1);
		splay(t1, 0);
		splay(t2, root);
		rev[ch[ch[root][1]][0]] ^= 1;
	}
	print(root);
	return 0;
}