Submission #1044589

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044589		vjudge1	Street Lamps (APIO19_street_lamps)	C++17	20 / 100	134 ms	10980 KiB

street_lamps

#include <bits/stdc++.h>

using i64 = long long;

#ifdef DEBUG
	#include "debug.h"
#else 
	#define debug(...) void(23)
#endif

#define def int mid = (l + r) >> 1, rv = v + ((mid - l + 1) << 1)
struct segtree {
	int n;
	std::vector<int> tree;
	segtree(int _n) : n(_n), tree(n << 1) {}

	void modify(int v, int l, int r, int p, int x) {
		if(l == r) {
			tree[v] = x;
			return;
		}
		def;
		if(p <= mid) {
			modify(v + 1, l, mid, p, x);
		} else {
			modify(rv, mid + 1, r, p, x);
		}
		tree[v] = std::max(tree[v + 1], tree[rv]);
	}
	void modify(int p, int x) {
		assert(0 <= p && p < n);
		modify(0, 0, n - 1, p, x);
	}

	int query(int v, int l, int r, int ql, int qr) {
		if(ql <= l && r <= qr) {
			return tree[v];
		}
		def;
		if(qr <= mid) {
			return query(v + 1, l, mid, ql, qr);
		} else if(mid + 1 <= ql) {
			return query(rv, mid + 1, r, ql, qr);
		}
		return std::max(query(v + 1, l, mid, ql, qr), 
						query(rv, mid + 1, r, ql, qr));
	}
	int query(int l, int r) {
		assert(0 <= l && l <= r && r < n);
		return query(0, 0, n - 1, l, r);
	}
};

constexpr int INF = 1E9;

int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(nullptr);

	int N, Q;
	std::cin >> N >> Q;
	std::string S;
	std::cin >> S;
	segtree seg(N);
	for(int i = 0; i < N; ++i) {
		if(S[i] == '1') {
			seg.modify(i, 0);
		} else {
			seg.modify(i, INF);
		}
	}

	for(int timer = 1; timer <= Q; ++timer) {
		std::string T;
		std::cin >> T;
		if(T[0] == 't') {
			int i;
			std::cin >> i;
			--i;
			if(S[i] == '1') {
				seg.modify(i, INF);
				S[i] = '0';
			} else {
				seg.modify(i, timer);
				S[i] = '1';
			}
		} else {
			int A, B;
			std::cin >> A >> B;
			--A, --B;
			int get = seg.query(A, B - 1);
			if(get == INF) {
				std::cout << 0 << '\n';
			} else {
				std::cout << timer - get << '\n';
			}
		}
		#ifdef DEBUG
			for(int i = 0; i < N; ++i) {
				std::cerr << seg.query(i, i) << " \n"[i == N - 1];
			}
		#endif
	}

	return 0;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20