题解 虚数之树

传送门

根据部分分发现树高是 \(\log\) 是可以做的
发现求的是距离，可以用点分治把树高弄成 \(\log\)
对每个节点开一个子树大小的线段树，存子树内在集合中的点到它的距离
修改和查询跳祖先即可
复杂度 \(O(n\log^2 n)\)

点击查看代码

#include <bits/stdc++.h>
using namespace std;
#define INF 0x3f3f3f3f
#define N 100010
#define fir first
#define sec second
#define pb push_back
#define ll long long
//#define int long long

char buf[1<<21], *p1=buf, *p2=buf;
#define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf, 1, 1<<21, stdin)), p1==p2?EOF:*p1++)
inline int read() {
	int ans=0, f=1; char c=getchar();
	while (!isdigit(c)) {if (c=='-') f=-f; c=getchar();}
	while (isdigit(c)) {ans=(ans<<3)+(ans<<1)+(c^48); c=getchar();}
	return ans*f;
}

int n, q, test_id, typ;
int head[N], ecnt;
struct edge{int to, next;}e[N<<1];
inline void add(int s, int t) {e[++ecnt]={t, head[s]}; head[s]=ecnt;}

namespace force{
	bool vis[N];
	int dep[N], fa[21][N], lg[N];
	void dfs(int u, int pa) {
		for (int i=1; i<21; ++i)
			if (dep[u]>=1<<i) fa[i][u]=fa[i-1][fa[i-1][u]];
			else break;
		for (int i=head[u],v; ~i; i=e[i].next) {
			v = e[i].to;
			if (v==pa) continue;
			fa[0][v]=u;
			dep[v]=dep[u]+1;
			dfs(v, u);
		}
	}
	int lca(int a, int b) {
		if (dep[a]<dep[b]) swap(a, b);
		while (dep[a]>dep[b]) a=fa[lg[dep[a]-dep[b]]-1][a];
		if (a==b) return a;
		for (int i=lg[dep[a]]-1; ~i; --i)
			if (fa[i][a]!=fa[i][b])
				a=fa[i][a], b=fa[i][b];
		return fa[0][a];
	}
	int dis(int a, int b) {return dep[a]+dep[b]-2*dep[lca(a, b)];}
	void solve() {
		dep[1]=1; dfs(1, 0);
		for (int i=1; i<=n; ++i) lg[i]=lg[i-1]+(1<<lg[i-1]==i);
		int lst=0, ans=0;
		for (int i=1,op,l,r,x; i<=q; ++i) {
			op=read();
			if (op==1) vis[read()^(lst*typ)]=1;
			else if (op==2) vis[read()^(lst*typ)]=0;
			else {
				l=read(); r=read(); x=read()^(lst*typ); ans=INF;
				for (int j=l; j<=r; ++j) if (vis[j]) ans=min(ans, dis(j, x));
				printf("%d\n", ans==INF?-1:ans);
				if (ans!=INF) lst=ans;
			}
		}
	}
}

namespace task1{
	bool del[N];
	int siz[N], msiz[N], rot;
	vector<pair<int, int>> anc[N];
	int lson[N*300], rson[N*300], val[N*300], tot;
	#define ls(p) lson[p]
	#define rs(p) rson[p]
	#define pushup(p) val[p]=min(val[ls(p)], val[rs(p)]);
	struct segment{
		int rot;
		void upd(int& p, int tl, int tr, int pos, int dat) {
			if (!p) val[p=++tot]=INF;
			if (tl==tr) {val[p]=dat; return ;}
			int mid=(tl+tr)>>1;
			if (pos<=mid) upd(ls(p), tl, mid, pos, dat);
			else upd(rs(p), mid+1, tr, pos, dat);
			pushup(p);
		}
		int query(int p, int tl, int tr, int ql, int qr) {
			if (!p) return INF;
			if (ql<=tl&&qr>=tr) return val[p];
			int mid=(tl+tr)>>1, ans=INF;
			if (ql<=mid) ans=min(ans, query(ls(p), tl, mid, ql, qr));
			if (qr>mid) ans=min(ans, query(rs(p), mid+1, tr, ql, qr));
			return ans;
		}
		void ins(int pos, int dat) {upd(rot, 1, n, pos, dat);}
		int query(int l, int r) {return query(rot, 1, n, l, r);}
	}seg[N];
	void getrt(int u, int fa, int tot) {
		siz[u]=1; msiz[u]=0;
		for (int i=head[u],v; ~i; i=e[i].next) {
			v = e[i].to;
			if (v==fa || del[v]) continue;
			getrt(v, u, tot);
			siz[u]+=siz[v];
			msiz[u]=max(msiz[u], siz[v]);
		}
		msiz[u]=max(msiz[u], tot-siz[u]);
		if (msiz[u]<msiz[rot]) rot=u;
	}
	void getdis(int u, int fa, int rot, int dis) {
		anc[u].pb({rot, dis});
		for (int i=head[u],v; ~i; i=e[i].next) {
			v = e[i].to;
			if (v==fa || del[v]) continue;
			getdis(v, u, rot, dis+1);
		}
	}
	void solve(int u) {
		del[u]=1;
		getdis(u, 0, u, 0);
		for (int i=head[u],v; ~i; i=e[i].next) {
			v = e[i].to;
			if (del[v]) continue;
			rot=0;
			getrt(v, u, siz[v]);
			solve(rot);
		}
	}
	void solve() {
		// cout<<double(sizeof(lson)*3+sizeof(seg))/1000/1000<<endl; exit(0);
		val[0]=INF;
		msiz[rot=0]=n+1;
		getrt(1, 0, n);
		solve(rot);
		int lst=0, ans=0;
		for (int i=1,op,l,r,x; i<=q; ++i) {
			op=read();
			if (op==1) {
				x=read()^(lst*typ);
				for (auto& it:anc[x]) seg[it.fir].ins(x, it.sec);
			}
			else if (op==2) {
				x=read()^(lst*typ);
				for (auto& it:anc[x]) seg[it.fir].ins(x, INF);
			}
			else {
				l=read(); r=read(); x=read()^(lst*typ); ans=INF;
				for (auto& it:anc[x]) ans=min(ans, it.sec+seg[it.fir].query(l, r));
				printf("%d\n", ans==INF?-1:ans);
				if (ans!=INF) lst=ans;
			}
		}
	}
}

signed main()
{
	freopen("regression.in", "r", stdin);
	freopen("regression.out", "w", stdout);

	n=read(); q=read(); test_id=read(); typ=read();
	memset(head, -1, sizeof(head));
	for (int i=1,u,v; i<n; ++i) {
		u=read(); v=read();
		add(u, v); add(v, u);
	}
	// force::solve();
	task1::solve();

	return 0;
}