[BZOJ2002][Hnoi2010]Bounce 弹飞绵羊 && LCT

最新推荐文章于 2019-09-05 09:49:58 发布

原创最新推荐文章于 2019-09-05 09:49:58 发布 · 352 阅读

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本文介绍了一种使用线段树结构来高效处理动态数据查询和更新的操作，包括节点大小维护、弹射器连接、虚拟节点引入等技巧，通过C++实现并优化查询效率。

对于每一个节点维护他的size

每一个弹射器由它即将到达的弹射器向他连边

虚拟一个n+1号节点进行最后一次弹射

每次直接查询对应位置的size即可

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
#include<queue>
#include<map>
#define SF scanf
#define PF printf
using namespace std;
typedef long long LL;
const int MAXN = 200000;
struct LCT {
	int ch[MAXN+10][2], fa[MAXN+10];
	int st[MAXN+10], sz[MAXN+10];
	bool rev[MAXN+10];
	bool isroot(int x) {
		return ch[fa[x]][0] != x && ch[fa[x]][1] != x;
	}
	void up(int x) {
		sz[x] = sz[ch[x][0]] + sz[ch[x][1]] + 1;
	}
	void pushdown(int x) {
		int &ls = ch[x][0], &rs = ch[x][1];
		if(rev[x]) {
			rev[x] ^= 1; rev[ls] ^= 1; rev[rs] ^= 1;
			swap(ls, rs);
		}
	}
	void Rotate(int x) {
		int y = fa[x], z = fa[y];
		bool d = x == ch[y][0];
 		if(!isroot(y)) ch[z][y == ch[z][1]] = x;
		fa[x] = z; fa[y] = x; fa[ch[x][d]] = y;
		ch[y][!d] = ch[x][d]; ch[x][d] = y;
		up(y);
	}
	void splay(int x) {
		int top = 0; st[++top] = x;
		for(int i = x; !isroot(i); i = fa[i]) st[++top] = fa[i];
		for(int i = top; i; i--) pushdown(st[i]);
		while(!isroot(x)) {
			int y = fa[x], z = fa[y];
			if(!isroot(y)) {
				if(ch[y][0] == x ^ ch[z][0] == y) Rotate(x);
				else Rotate(y);
			}
			Rotate(x);
		}
		up(x);
	}
	void access(int x) {
		int t = 0;
		while(x) {
			splay(x);
			ch[x][1] = t;
			t = x; x = fa[x];
		}
	}
	void makeroot(int x) {
		access(x); splay(x); rev[x] ^= 1;
	}
	void link(int x, int y) {
		makeroot(x); fa[x] = y; splay(x);
	}
	void cut(int x, int y) {
		makeroot(x); access(y); splay(y); ch[y][0] = fa[x] = 0;
	}
	int find(int x) {
		access(x); splay(x);
		int y = x;
		while(ch[y][0]) y = ch[y][0];
		return y;
	}
} sp;
int n, m;
int Nex[MAXN+10];
int main() 
{
	SF("%d", &n);
	for(int i = 1; i <= n; i++) {
		int x; SF("%d", &x);
		sp.fa[i] = i+x; sp.sz[i] = 1;
		if(i+x > n+1) sp.fa[i] = n+1;
		Nex[i] = sp.fa[i];
	}
	sp.sz[n+1] = 1;
	SF("%d", &m);
	for(int i = 1; i <= m; i++) {
		int op, x, y;
		SF("%d", &op);
		if(op == 1) {
			SF("%d", &x); x++;
			sp.makeroot(n+1);
			sp.access(x); sp.splay(x); PF("%d\n", sp.sz[sp.ch[x][0]]);
		}
		else {
			SF("%d%d", &x, &y); x++;
			int New = min(n+1, x+y);
			sp.cut(x, Nex[x]); Nex[x] = New;
			sp.link(x, Nex[x]);
		}
	}
}