Submission #387330

#	Time	Username	Problem	Language	Result	Execution time	Memory
387330		SeDunion	Event Hopping 2 (JOI21_event2)	C++17	100 / 100	722 ms	88296 KiB

event2

#include<bits/stdc++.h>
#ifndef LOCAL
#define cerr if(false)cerr
#endif // LOCAL
using namespace std;
using ll = long long;
const int N = 1e6 + 66;
const int LOG = 20;

struct el {
	int l, r, i;
} e[N];

int n, k;

int sp[N][LOG];

int cnt(int l, int r) {
	int res = 0;
	for (int j = LOG - 1 ; j >= 0 ; -- j) {
		if (sp[l][j] <= r) {
			res += (1 << j);
			l = sp[l][j];
		}
	}
	return res;
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	cin >> n >> k;
	vector<int>vals;
	for (int i = 1 ; i <= n ; ++ i) {
		cin >> e[i].l >> e[i].r; e[i].i = i;
		vals.emplace_back(e[i].l);
		vals.emplace_back(e[i].r);
	}
	sort(vals.begin(), vals.end());
	for (int i = 1 ; i <= n ; ++ i) {
		e[i].l = lower_bound(vals.begin(), vals.end(), e[i].l) - vals.begin();
		e[i].r = lower_bound(vals.begin(), vals.end(), e[i].r) - vals.begin();
	}
	for (int j = 0 ; j < LOG ; ++ j) for (int i = 0 ; i < N ; ++ i) sp[i][j] = N - 1;
	for (int i = 1 ; i <= n ; ++ i) {
		sp[e[i].l][0] = min(sp[e[i].l][0], e[i].r);
	}
	for (int i = N - 1 ; i > 0 ; -- i) {
		sp[i - 1][0] = min(sp[i - 1][0], sp[i][0]);
	}
	for (int j = 1 ; j < LOG ; ++ j) {
		for (int i = 0 ; i < N ; ++ i) {
			sp[i][j] = sp[sp[i][j - 1]][j - 1];
		}
		for (int i = N - 1 ; i > 0 ; -- i) {
			sp[i - 1][j] = min(sp[i - 1][j], sp[i][j]);
		}
	}
	set<pair<int,int>>s={{0, N - 2}};
	int cur = cnt(0, N - 2);
	if (cur < k) {
		cout << -1;
		return 0;
	}
	vector<int>ans;
	for (int i = 1 ; i <= n ; ++ i) {
		int L = e[i].l, R = e[i].r;
		auto it = s.upper_bound(pair{L, N});
		it--;
		int l = it->first, r = it->second;
		if (l <= L && R <= r) {
			if (cur + 1 - cnt(l, r) + cnt(l, L) + cnt(R, r) >= k) {
				cur = cur + 1 - cnt(l, r) + cnt(l, L) + cnt(R, r);
				ans.emplace_back(i);
				s.erase(it);
				s.insert({l, L});
				s.insert({R, r});
			}
		}
		if ((int)ans.size() == k) {
			break;
		}
	}
	sort(ans.begin(), ans.end());
	for (int i : ans) cout << i << "\n";
	//assert((int)ans.size() == k);
}

• Subtask 1: 7 / 7
• Subtask 2: 1 / 1
• Subtask 3: 31 / 31
• Subtask 4: 61 / 61