Submission #260515

#	Time	Username	Problem	Language	Result	Execution time	Memory
260515		islingr	Street Lamps (APIO19_street_lamps)	C++17	100 / 100	3501 ms	55268 KiB

street_lamps

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

#define rep(i, a, b) for (auto i = (a); i < (b); ++i)

const int N = 1 << 19;
struct { int l, r, t, del; } a[3 * N], b[3 * N];
int q, ans[N];

void cdq2(int l, int r) {
	if (r - l == 1) return;
	int m = (l + r) >> 1;
	cdq2(l, m); cdq2(m, r);
	rep(i, l, r) b[i].r = i < m;
	inplace_merge(b + l, b + m, b + r, [&](const auto &a, const auto &b) { return a.t < b.t; });
	int s = 0;
	rep(i, l, r) {
		if (b[i].del && b[i].l && b[i].r) s += b[i].del * b[i].t;
		if (!b[i].del && !b[i].l && !b[i].r) ans[b[i].t] += s;
	}
}

void cdq1(int l, int r) {
	if (r - l == 1) return;
	int m = (l + r) >> 1;
	cdq1(l, m); cdq1(m, r);
	rep(i, l, r) a[i].l = i < m;
	merge(a + l, a + m, a + m, a + r, b + l, [&](const auto &a, const auto &b) { return pair(a.r, a.del & 1) > pair(b.r, b.del & 1); });
	rep(i, l, r) a[i] = b[i];
	cdq2(l, r);
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n, p = 0; cin >> n >> q; int pre = -1;
	set<int> z = {-1};
	rep(i, 0, n) {
		char c; cin >> c;
		if (c != '0') {
			if (p && a[p - 1].r == i) a[p - 1].r = i + 1;
			else a[p++] = {pre + 1, i + 1, -1, -1};
		} else z.insert(pre = i);
	}
	z.insert(n);

	rep(t, 0, q) {
		string s; cin >> s;
		if (s == "toggle") {
			int i; cin >> i; --i;
			auto [it, f] = z.insert(i);
			int d = f ? +1 : -1;
			a[p++] = {*prev(it) + 1, *next(it), t, +d};
			a[p++] = {*prev(it) + 1, i, t, -d};
			a[p++] = {i + 1, *next(it), t, -d};
			if (d < 0) z.erase(it);
			ans[t] = -1;
		} else {
			int l, r; cin >> l >> r; --l; --r;
			a[p++] = {l, r, t, 0};
			ans[t] = *z.lower_bound(l) < r ? 0 : t;
		}
	}

	sort(a, a + p, [&](const auto &a, const auto &b) { return pair(-a.l, a.del & 1) > pair(-b.l, b.del & 1); });
	cdq1(0, p);
	rep(t, 0, q) if (0 <= ans[t]) cout << ans[t] << '\n';
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20