Submission #885006

#	Time	Username	Problem	Language	Result	Execution time	Memory
885006		MinaRagy06	Jail (JOI22_jail)	C++17	100 / 100	519 ms	48068 KiB

jail

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define md ((l + r) >> 1)

const int N = 120'005;
vector<int> adj[N];
int st[N], en[N], h[N], anc[N][17], t;
void dfs(int i, int par, int d = 0) {
	anc[i][0] = par;
	for (int j = 1; j < 17; j++) {
		anc[i][j] = anc[anc[i][j - 1]][j - 1];
	}
	h[i] = d;
	st[i] = t++;
	for (auto nxt : adj[i]) {
		if (nxt == par) continue;
		dfs(nxt, i, d + 1);
	}
	en[i] = t - 1;
}
int getlca(int u, int v) {
	if (st[u] <= st[v] && en[v] <= en[u]) {
		return u;
	}
	for (int j = 16; j >= 0; j--) {
		int nxtu = anc[u][j];
		if (!(st[nxtu] <= st[v] && en[v] <= en[nxtu])) {
			u = nxtu;
		}
	}
	return anc[u][0];
}
struct path {
	int s, e, lca;
} a[N];
const int inf = 1e9;
int n, m;
struct segtree {
	array<int, 2> seg[1 << 18];
	void build(int i, int l, int r) {
		if (l == r) {
			seg[i] = {-inf, -inf};
			return;
		}
		build(i << 1, l, md);
		build(i << 1 | 1, md + 1, r);
		seg[i] = max(seg[i << 1], seg[i << 1 | 1]);
	}
	void assign(int i, int l, int r, int x, array<int, 2> v) {
		if (l == r) {
			seg[i] = v;
			return;
		}
		if (x <= md) {
			assign(i << 1, l, md, x, v);
		} else {
			assign(i << 1 | 1, md + 1, r, x, v);
		}
		seg[i] = max(seg[i << 1], seg[i << 1 | 1]);
	}
	void erase(int i, int l, int r, int x) {
		if (l == r) {
			seg[i] = {-inf, -inf};
			return;
		}
		if (x <= md) {
			erase(i << 1, l, md, x);
		} else {
			erase(i << 1 | 1, md + 1, r, x);
		}
		seg[i] = max(seg[i << 1], seg[i << 1 | 1]);
	}
	array<int, 2> query(int i, int l, int r, int s, int e) {
		if (s <= l && r <= e) {
			return seg[i];
		}
		if (r < s || e < l) {
			return {-inf, -inf};
		}
		return max(query(i << 1, l, md, s, e), query(i << 1 | 1, md + 1, r, s, e));
	}
	void assign(int i, array<int, 2> v) {
		assign(1, 0, n - 1, i, v);
	}
	void erase(int i) {
		erase(1, 0, n - 1, i);
	}
	array<int, 2> query(int l, int r) {
		array<int, 2> ret = query(1, 0, n - 1, l, r);
		return ret;
	}
	void init() {
		build(1, 0, n - 1);
	}
} seg1, seg2, seg3;
bool vis[N], instack[N];
void assign(int i) {
	vis[i] = 0;
	seg1.assign(st[a[i].s], {en[a[i].s], i});
	seg2.assign(st[a[i].s], {-st[a[i].lca], i});
	seg3.assign(st[a[i].e], {-st[a[i].lca], i});
}
void rem(int i) {
	vis[i] = 1;
	seg1.erase(st[a[i].s]);
	seg2.erase(st[a[i].s]);
	seg3.erase(st[a[i].e]);
}
bool dfs2(int i) {
	instack[i] = 1;
	bool ok = 1;
	rem(i);
	auto go = [&] (int j) {
		if (instack[j]) {
			ok = 0;
			return;
		}
		assign(i);
		bool ret = dfs2(j);
		rem(i);
		if (!ret) {
			ok = 0;
		}
	};
	array<int, 2> val;
	val = seg1.query(st[a[i].lca], st[a[i].s]);
	while (ok && val[0] >= st[a[i].s]) {
		int j = val[1];
		go(j);
		val = seg1.query(st[a[i].lca], st[a[i].s]);
	}
	
	val = seg1.query(st[a[i].lca], st[a[i].e]);
	while (ok && val[0] >= st[a[i].e]) {
		int j = val[1];
		go(j);
		val = seg1.query(st[a[i].lca], st[a[i].e]);
	}

	val = seg2.query(st[a[i].e], en[a[i].e]);
	val[0] *= -1;
	while (ok && val[0] <= st[a[i].e]) {
		int j = val[1];
		go(j);
		val = seg2.query(st[a[i].e], en[a[i].e]);
		val[0] *= -1;
	}
	
	val = seg3.query(st[a[i].e], en[a[i].e]);
	val[0] *= -1;
	while (ok && val[0] <= st[a[i].e]) {
		int j = val[1];
		go(j);
		val = seg3.query(st[a[i].e], en[a[i].e]);
		val[0] *= -1;
	}
	instack[i] = 0;
	return ok;
// 	for (int j = 0; j < m; j++) {
// 		if (j == i) continue;
// 		if (vis[j]) continue;
// 		bool gud = 0;
// 		gud |= st[a[i].lca] <= st[a[j].s] && st[a[j].s] <= st[a[i].s] && en[a[j].s] >= st[a[i].s]; //segtree 1
// 		gud |= st[a[i].lca] <= st[a[j].s] && st[a[j].s] <= st[a[i].e] && en[a[j].s] >= st[a[i].e]; //segtree 1
// 		gud |= st[a[i].e] <= st[a[j].s] && st[a[j].s] <= en[a[i].e] && st[a[j].lca] <= st[a[i].e]; //segtree 2
// 		gud |= st[a[i].e] <= st[a[j].e] && st[a[j].e] <= en[a[i].e] && st[a[j].lca] <= st[a[i].e]; //segtree 3
// 		if (gud) {
// 			if (instack[j]) {
// 				ok = 0;
// 				break;
// 			}
// 			if (!dfs2(j)) {
// 				ok = 0;
// 				break;
// 			}
// 		}
// 	}
}
int main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	int T;
	cin >> T;
	while (T--) {
		cin >> n;
		for (int i = 0; i < n; i++) {
			adj[i].clear();
			vis[i] = 0;
			instack[i] = 0;
		}
		for (int i = 1, u, v; i < n; i++) {
			cin >> u >> v;
			u--, v--;
			adj[u].push_back(v);
			adj[v].push_back(u);
		}
		t = 0;
		dfs(0, 0);
		cin >> m;
		for (int i = 0; i < m; i++) {
			cin >> a[i].s >> a[i].e;
			a[i].s--, a[i].e--;
			a[i].lca = getlca(a[i].s, a[i].e);
// 			cout << a[i].s + 1 << ' ' << a[i].e + 1 << ' ' << a[i].lca + 1 << '\n';
		}
		seg1.init();
		seg2.init();
		seg3.init();
		for (int i = 0; i < m; i++) {
			assign(i);
		}
		bool ok = 1;
		for (int i = 0; i < m; i++) {
			if (vis[i]) continue;
			if (!dfs2(i)) {
				ok = 0;
			}
		}
		cout << (ok? "Yes\n" : "No\n");
	}
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 16 / 16
• Subtask 4: 28 / 28
• Subtask 5: 12 / 12
• Subtask 6: 11 / 11
• Subtask 7: 23 / 23