Submission #1044967

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044967		vjudge1	Street Lamps (APIO19_street_lamps)	C++17	40 / 100	73 ms	22604 KiB

street_lamps

#include <bits/stdc++.h>
#define fast cin.tie(0)->sync_with_stdio(0);
#define int long long
#define inf ((int)1e18)
using namespace std;

void solve1(int n, int q, string s, vector<array<int, 3> > Q) {
	vector <string> states;
	states.push_back(s);
	for(int i = 0; i < q; i++) {
		auto [t, a, b] = Q[i];
		if(t == 2) {
			int ans = 0;
			for(auto it:states) {
				bool yes = 1;
				for(int i = a - 1; i < b - 1; i++) {
					if(it[i] != '1') {
						yes = 0;
						break;
					}
				}
				ans += yes;
			}
			states.push_back(states.back());
			cout << ans << "\n";
		}
		else {
			int ind = a;
			string p = states.back();
			p[ind - 1] = (p[ind - 1] - '0' + 1) % 2 + '0';
			states.push_back(p);
		}
	}
}

void solve2(int n, int q, string s, vector<array<int, 3> > Q) {
	vector <int> till(n, -1), ans(n); // till[ind] = 0 means closed
	for(int i = 0; i < n; i++) {
		if(s[i] == '1') till[i] = 0;
	}
	for(int i = 1; i <= q; i++) {
		auto [t, a, b] = Q[i - 1];
		if(t == 1) {
			int ind = a;
			ind--;
			if(~till[ind]) {
				ans[ind] += i - till[ind];
				till[ind] = -1;
			}
			else {
				till[ind] = i;
			}
		}
		else {
			a--, b-=2;
			int tmp = (~till[a]) ? i - till[a] : 0;
			cout << tmp + ans[a] << "\n";
		}
	}
}

struct segtree {
	int n;
	vector <int> t;
	void init(int size) {
		n = size;
		t.resize(n * 4);
	}
	void update(int v, int l, int r, int ind, int val) {
		if(l == r) {
			t[v] = val;
			return;
		}
		int m = (l + r) / 2;
		if(ind <= m) {
			update(v * 2, l, m, ind, val);
		}
		else {
			update(v * 2 + 1, m + 1, r, ind, val);
		}
		t[v] = max(t[v * 2], t[v * 2 + 1]);
	}
	int query(int v, int l, int r, int ql, int qr) {
		if(l >= ql and r <= qr) {
			return t[v];
		}
		int m = (l + r) / 2;
		int ret = 0;
		if(ql <= m) {
			ret = max(ret, query(v * 2, l, m, ql, qr));
		}
		if(qr > m) {
			ret = max(ret, query(v * 2 + 1, m + 1, r, ql, qr));
		}
		return ret;
	}
};

void solve3(int n, int q, string s, vector<array<int, 3> > Q) {
	segtree t;
	t.init(n);
	for(int i = 0; i < n; i++) {
		if(s[i] == '1') t.update(1, 0, n - 1, i, 0);
	}
	for(int i = 1; i <= q; i++) {
		auto [type, a, b] = Q[i - 1];
		if(type == 1) {
			int ind = a;
			ind--;
			t.update(1, 0, n - 1, ind, i);
		}
		else {
			a--, b -= 2;
			cout << i - t.query(1, 0, n - 1, a, b) << "\n";
		}
	}
}

int32_t main(){
	fast
	int n, q;
	cin >> n >> q;
	string s;
	cin >> s;
	vector <array<int, 3> > queries;
	bool yes = 0;
	for(int i = 0; i < q; i++) {
		string type;
		cin >> type;
		if(type == "toggle") {
			int ind;
			cin >> ind;
			queries.push_back({1, ind, 0});
		}
		else {
			int a, b;
			cin >> a >> b;
			if(b - a > 1) yes = 1;
			queries.push_back({2, a, b});
		}
	}
	if(!yes) {
		solve2(n, q, s, queries);
	}
	else if(n <= 100 and q <= 100) {
		solve1(n, q, s, queries);
	}
	else {
		solve3(n, q, s, queries);
	}
}

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