Submission #704043

#	Time	Username	Problem	Language	Result	Execution time	Memory
704043		flappybird	Event Hopping 2 (JOI21_event2)	C++17	100 / 100	209 ms	32632 KiB

event2

#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define MAX 201010
#define MAXS 20
#define INF 1000000000000000001
#define bb ' '
#define ln '\n'
#define Ln '\n'
int S[MAX];
int E[MAX];
vector<int> st[MAX];
int sp[MAX][MAXS];
int getnum(int l, int r) {
	int ans = 0;
	int i;
	for (i = MAXS - 1; i >= 0; i--) if (sp[l][i] <= r) l = sp[l][i], ans |= (1 << i);
	return ans;
}
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	int N, K;
	cin >> N >> K;
	int i;
	vector<int> v;
	for (i = 1; i <= N; i++) {
		cin >> S[i] >> E[i];
		v.push_back(S[i]);
		v.push_back(E[i]);
	}
	sort(v.begin(), v.end());
	v.erase(unique(v.begin(), v.end()), v.end());
	for (i = 1; i <= N; i++) {
		S[i] = lower_bound(v.begin(), v.end(), S[i]) - v.begin() + 1;
		E[i] = lower_bound(v.begin(), v.end(), E[i]) - v.begin() + 1;
	}
	int X = v.size();
	for (i = 1; i <= N; i++) st[S[i]].push_back(E[i]);
	int mn = X + 1;
	for (i = 0; i < MAXS; i++) sp[X + 1][i] = X + 1;
	for (i = X; i >= 1; i--) {
		for (auto v : st[i]) mn = min(mn, v);
		sp[i][0] = mn;
	}
	int j;
	for (i = 1; i < MAXS; i++) for (j = 1; j <= X; j++) sp[j][i] = sp[sp[j][i - 1]][i - 1];
	set<pii> st;
	st.insert(pii(1, X));
	vector<int> ans;
	int sum = getnum(1, X);
	for (i = 1; i <= N; i++) {
		int s = S[i], e = E[i];
		auto it = st.lower_bound(pii(s + 1, -1e9));
		if (it-- == st.begin()) continue;
		auto [l, r] = *it;
		if (!(l <= s && e <= r)) continue;
		int delta = -getnum(l, r) + getnum(l, s) + getnum(e, r) + 1;
		if (sum + delta < K) continue;
		sum += delta;
		st.erase(it);
		st.emplace(l, s);
		st.emplace(e, r);
		ans.push_back(i);
		if (ans.size() == K) break;
	}
	if (ans.size() < K) {
		cout << -1 << ln;
		return 0;
	}
	for (auto v : ans) cout << v << ln;
}

Compilation message (stderr)

event2.cpp: In function 'int main()':
event2.cpp:70:18: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   70 |   if (ans.size() == K) break;
      |       ~~~~~~~~~~~^~~~
event2.cpp:72:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   72 |  if (ans.size() < K) {
      |      ~~~~~~~~~~~^~~

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