文艺平衡树

标签：math   temp   平衡   algo   print   oca   inf   name   queue   

#include<iostream>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<cstdlib>
#include<climits>
#include<stack>
#include<vector>
#include<queue>
#include<set>
#include<bitset>
#include<map>
//#include<regex>
#include<cstdio>
#include <iomanip>
#pragma GCC optimize(2)
#define up(i,a,b)  for(int i=a;i<b;i++)
#define dw(i,a,b)  for(int i=a;i>b;i--)
#define upd(i,a,b) for(int i=a;i<=b;i++)
#define dwd(i,a,b) for(int i=a;i>=b;i--)
//#define local
typedef long long ll;
typedef unsigned long long ull;
const double esp = 1e-6;
const double pi = acos(-1.0);
const int INF = 0x3f3f3f3f;
const int inf = 1e9;
using namespace std;
ll read()
{
	char ch = getchar(); ll x = 0, f = 1;
	while (ch<‘0‘ || ch>‘9‘) { if (ch == ‘-‘)f = -1; ch = getchar(); }
	while (ch >= ‘0‘ && ch <= ‘9‘) { x = x * 10 + ch - ‘0‘; ch = getchar(); }
	return x * f;
}
typedef pair<int, int> pir;
#define lson l,mid,root<<1
#define rson mid+1,r,root<<1|1
#define lrt root<<1
#define rrt root<<1|1
const int N = 1e5 + 10;
int root, tot;
struct node {
	int ch[2], fa, sz, cnt, val, lazy;
}tree[N];
int a[N];
void pushup(int rt)
{
	tree[rt].sz = tree[tree[rt].ch[0]].sz + tree[tree[rt].ch[1]].sz + tree[rt].cnt;
}
void pushdown(int rt)
{
	if (rt&&tree[rt].lazy)
	{
		int ls = tree[rt].ch[0];
		int rs = tree[rt].ch[1];
		swap(tree[rt].ch[0], tree[rt].ch[1]);
		tree[ls].lazy ^= 1;
		tree[rs].lazy ^= 1;
		tree[rt].lazy = 0;
	}
}
bool ident(int u, int fa)
{
	return tree[fa].ch[1] == u;
}
void connect(int u,int fa,int son) {
	tree[u].fa = fa;
	tree[fa].ch[son] = u;
}
void rotate(int u)
{
	int f = tree[u].fa; int ff = tree[f].fa;
	int isson = ident(u, f);
	connect(u, ff, ident(f,ff));
	connect(tree[u].ch[isson ^ 1], f, isson);
	connect(f, u, isson ^ 1);
	pushup(f); pushup(u);
}
void splay(int u, int goal)
{
	while (tree[u].fa != goal)
	{
		int f = tree[u].fa;
		int ff = tree[f].fa;
		if (ff != goal)
			(ident(f, ff) ^ (ident(u, f))) ? rotate(u) : rotate(f);
		rotate(u);
	}
	if (goal == 0)root = u;
}
int K_th(int k)
{
	int u = root;
	if (tree[u].sz < k)return -1;
	while (23)
	{
		pushdown(u);
		int v = tree[u].ch[0];
		if (k > tree[v].sz + tree[u].cnt)
		{
			k -= tree[v].sz + tree[u].cnt;
			u = tree[u].ch[1];
		}
		else {
			if (tree[v].sz >= k)
				u = v;
			else return u;
		}
	}
}
void build(int l, int r,int fa,int &o)
{
	if (l > r)return;
	o = ++tot;
	int now = o;
	int mid = (l + r) >> 1;
	tree[now].val = a[mid];
	tree[now].cnt = 1;
	tree[now].fa = fa;
	tree[now].cnt = 1;
	build(l, mid - 1, now, tree[now].ch[0]);
	build(mid + 1, r, now, tree[now].ch[1]);
	pushup(now);
}
void rever(int l, int r)
{
	int L = l; int R = r + 2;
	int templ = K_th(L); int tempr = K_th(R);
	splay(templ, 0); splay(tempr, templ);
	int temprson = tree[tempr].ch[0];
	tree[temprson].lazy ^= 1;
}
void print(int o)
{
	if (!o)return;
	pushdown(o);
	print(tree[o].ch[0]);
	if (tree[o].val != INF && tree[o].val != -INF)
		printf("%d ", tree[o].val);
	print(tree[o].ch[1]);
}
int main()
{
	int n, m;
	n = read(), m = read();
	upd(i, 1, n)
		a[i + 1] = i;
	a[1] = -INF; a[2 + n] = INF;
	build(1, n + 2, 0, root);
	root = 1;
	int l, r;
	while (m--)
	{
		l = read(), r = read();
		rever(l, r);
	}
	print(root);
}

文艺平衡树

标签：math   temp   平衡   algo   print   oca   inf   name   queue   

原文地址：https://www.cnblogs.com/LORDXX/p/13210774.html