Submission #916802

#	Time	Username	Problem	Language	Result	Execution time	Memory
916802		happypotato	Long Mansion (JOI17_long_mansion)	C++17	20 / 100	3047 ms	26196 KiB

long_mansion

#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define ff first
#define ss second
const int mxN = 5e5 + 1;
const int MAX = 1e9, MIN = -1e9;
pii seg[(1 << 20)];
pii a[mxN];
int corr[mxN];
vector<int> keys[mxN];
int n;
void build(int l = 1, int r = n, int idx = 1) {
	if (l == r) {
		seg[idx] = a[l];
		return;
	}
	int mid = (l + r) >> 1;
	build(l, mid, (idx << 1));
	build(mid + 1, r, (idx << 1) | 1);
	seg[idx].ff = min(seg[(idx << 1)].ff, seg[(idx << 1) | 1].ff);
	seg[idx].ss = max(seg[(idx << 1)].ss, seg[(idx << 1) | 1].ss);
}
int querymin(int tl, int tr, int l = 1, int r = n, int idx = 1) {
	if (tl <= l && r <= tr) return seg[idx].ff;
	int mid = (l + r) >> 1;
	int res = MAX;
	if (tl <= mid) res = min(res, querymin(tl, tr, l, mid, (idx << 1)));
	if (tr > mid) res = min(res, querymin(tl, tr, mid + 1, r, (idx << 1) | 1));
	return res;
}
int querymax(int tl, int tr, int l = 1, int r = n, int idx = 1) {
	if (tl <= l && r <= tr) return seg[idx].ss;
	int mid = (l + r) >> 1;
	int res = MIN;
	if (tl <= mid) res = max(res, querymax(tl, tr, l, mid, (idx << 1)));
	if (tr > mid) res = max(res, querymax(tl, tr, mid + 1, r, (idx << 1) | 1));
	return res;
}
map<pii, bool> sto;
bool recur(int x, int y) {
	// cout << x << ' ' << y << endl;
	if (sto.find({x, y}) != sto.end()) return sto[{x, y}];
	sto[{x, y}] = false;
	if (x < y) {
		int req = querymin(x + 1, y);
		if (x <= req) return sto[{x, y}] = true;
		if (req == MIN) return sto[{x, y}] = false;
		return sto[{x, y}] = recur(x, req);
	} else if (x > y) {
		int req = querymax(y, x - 1);
		if (req <= x) return sto[{x, y}] = true;
		if (req == MAX) return sto[{x, y}] = false;
		return sto[{x, y}] = recur(x, req);
	} else return true;
}
int occur[mxN];
void solve() {
	cin >> n;
	for (int i = 1; i < n; i++) cin >> corr[i];
	for (int i = 1; i <= n; i++) {
		int sz; cin >> sz;
		keys[i].resize(sz);
		for (int &x : keys[i]) cin >> x;
	}

	// sweep from left to right, take min of max
	for (int i = 1; i <= n; i++) occur[i] = MIN;
	a[1].ff = MIN;
	for (int i = 1; i < n; i++) {
		for (int x : keys[i]) occur[x] = i;
		a[i + 1].ff = occur[corr[i]];
	}
	// sweep from right to left, take max of min
	for (int i = 1; i <= n; i++) occur[i] = MAX;
	a[n].ss = MAX;
	for (int i = n; i > 1; i--) {
		for (int x : keys[i]) occur[x] = i;
		a[i - 1].ss = occur[corr[i - 1]];
	}

	// for (int i = 1; i <= n; i++) {
	// 	cout << i << ": " << a[i].ff << ' ' << a[i].ss << endl;
	// }
	build();

	int q; cin >> q;
	while (q--) {
		int x, y;
		cin >> x >> y;
		cout << (recur(x, y) ? "YES\n" : "NO\n");
		sto.clear();
	}
}
int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	solve();
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 5
• Subtask 3: 15 / 15
• Subtask 4: 0 / 75