Submission #984854

#	Time	Username	Problem	Language	Result	Execution time	Memory
984854		pavement	Escape Route 2 (JOI24_escape2)	C++17	23 / 100	214 ms	31596 KiB

Main

#include <bits/stdc++.h>
using namespace std;

using ii = pair<int, int>;
using ll = long long;

#define mp make_pair
#define pb push_back
#define eb emplace_back

int N, T, Q, _idx, M[100005], min_width[100005], anc[25][100005];
ll dep[100005];
vector<int> idx[100005];
vector<ii> V[100005], rngs[100005];

ll f(int u, int k) {
	int v = u;
	for (int j = 20; j >= 0; j--) {
		if (k & (1 << j)) {
			v = anc[j][v];
		}
	}
	assert(v);
	return dep[u] - dep[v];
}

ll is(ii a, ii b, int lim) {
	int lo = 0, hi = lim, ret = (int)1e9;
	while (lo <= hi) {
		int mid = (lo + hi) / 2;
		if (f(a.first, mid) + a.second <= f(b.first, mid) + b.second) {
			ret = mid;
			hi = mid - 1;
		} else {
			lo = mid + 1;
		}
	}
	return ret;
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> N >> T;
	for (int i = 1; i < N; i++) {
		cin >> M[i];
		min_width[i] = 2e9;
		for (int j = 0, a, b; j < M[i]; j++) {
			cin >> a >> b;
			min_width[i] = min(min_width[i], b - a);
			V[i].eb(a, b);
			idx[i].pb(++_idx);
		}
		sort(V[i].begin(), V[i].end());
		for (int j = (int)V[i].size() - 1, sf = (int)2e9; j >= 0; j--) {
			sf = min(sf, V[i][j].second);
			V[i][j].second = sf;
		}
	}
	for (int i = N - 2; i >= 1; i--) {
		for (int j = 0; j < M[i]; j++) {
			assert(!V[i + 1].empty());
			int tmp = lower_bound(V[i + 1].begin(), V[i + 1].end(), mp(V[i][j].second, -1)) - V[i + 1].begin();
			ii potential_to = mp(V[i + 1][0].second + T - V[i][j].second, idx[i + 1][0]);
			if (tmp < (int)V[i + 1].size()) {
				potential_to = min(potential_to, mp(V[i + 1][tmp].second - V[i][j].second, idx[i + 1][tmp]));
			}
			anc[0][idx[i][j]] = potential_to.second;
			for (int k = 1; k <= 20; k++) {
				if (anc[k - 1][idx[i][j]] == 0) {
					break;
				}
				anc[k][idx[i][j]] = anc[k - 1][anc[k - 1][idx[i][j]]];
			}
			dep[idx[i][j]] = dep[potential_to.second] + potential_to.first;
		}
	}
	for (int i = 1; i < N; i++) {
		int mn = *min_element(idx[i].begin(), idx[i].end());
		sort(idx[i].begin(), idx[i].end(), [&](const auto &lhs, const auto &rhs) {
			return V[i][lhs - mn].second > V[i][rhs - mn].second;
		});
		vector<ii> copy_V(V[i].begin(), V[i].end());
		for (int j = 0; j < M[i]; j++) {
			V[i][j] = copy_V[idx[i][j] - mn];
			while (rngs[i].size() > 1 && is(rngs[i][rngs[i].size() - 1], mp(idx[i][j], V[i][j].second - V[i][j].first), N - i - 1) <= is(rngs[i][rngs[i].size() - 2], rngs[i][rngs[i].size() - 1], N - i - 1)) {
				rngs[i].pop_back();
			}
			rngs[i].eb(idx[i][j], V[i][j].second - V[i][j].first);
		}
	}
	cin >> Q;
	for (int L, R; Q--; ) {
		cin >> L >> R;
		if (L + 1 == R) {
			cout << min_width[L] << '\n';
			continue;
		}
		ll ans = (ll)1e18;
		for (auto [x, y] : rngs[L]) {
			ans = min(ans, f(x, R - L - 1) + y);
		}
		cout << ans << '\n';
	}
}

• Subtask 1: 6 / 6
• Subtask 2: 0 / 8
• Subtask 3: 17 / 17
• Subtask 4: 0 / 23
• Subtask 5: 0 / 36
• Subtask 6: 0 / 10