제출 #1277056

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1277056		SmuggingSpun	Event Hopping 2 (JOI21_event2)	C++20	100 / 100	150 ms	27524 KiB

event2

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
const int lim = 1e5 + 5;
template<class T>void minimize(T& a, T b){
	if(a > b){
		a = b;
	}
}
int n, k, l[lim], r[lim];
namespace sub2{
	void solve(){
		vector<int>p, best;
		for(int mask = (1 << n) - 1; mask > 0; mask--){
			if(__builtin_popcount(mask) == k){
				p.clear();
				for(int i = 0; i < n; i++){
					if(mask >> i & 1){
						p.push_back(i + 1);
					}
				}
				sort(p.begin(), p.end(), [&] (int i, int j){
					return l[i] < l[j];
				});
				for(int i = 1; i < k; i++){
					if(l[p[i]] < r[p[i - 1]]){
						p.clear();
						break;
					}
				}
				if(!p.empty()){
					sort(p.begin(), p.end());
					if(best.empty() || p < best){
						swap(best, p);
					}
				}
			}
		}
		if(best.empty()){
			return void(cout << "-1\n");
		}
		for(int& x : best){
			cout << x << "\n";
		}
	}
}
namespace sub134{
	void solve(){
		vector<int>id;
		for(int i = 1; i <= n; i++){
			id.push_back(l[i]);
			id.push_back(r[i]);
		}
		sort(id.begin(), id.end());
		id.resize(unique(id.begin(), id.end()) - id.begin());
		int N = id.size();
		vector<vector<int>>up(N + 1, vector<int>(18, N));
		for(int i = 1; i <= n; i++){
			minimize(up[l[i] = lower_bound(id.begin(), id.end(), l[i]) - id.begin()][0], r[i] = lower_bound(id.begin(), id.end(), r[i]) - id.begin());
		}
		for(int i = N - 1; i > -1; i--){
			minimize(up[i][0], up[i + 1][0]);
		}
		for(int j = 1; j < 18; j++){
			for(int i = 0; i < N; i++){
				up[i][j] = up[up[i][j - 1]][j - 1];
			}
		}
		set<pair<int, int>>range;
		range.insert(make_pair(0, N - 1));
		function<int(int, int)>calc = [&] (int L, int R){
			int ans = 0;
			for(int i = 17; i > -1; i--){
				if(up[L][i] <= R){
					ans |= 1 << i;
					L = up[L][i];
				}
			}
			return ans;
		};
		int cnt = calc(0, N - 1);
		if(cnt < k){
			return void(cout << -1);
		}
		vector<int>ans;
		for(int i = 1; ans.size() < k; i++){
			set<pair<int, int>>::iterator it = range.lower_bound(make_pair(l[i], INT_MAX));
			if(it == range.begin()){
				continue;
			}
			pair<int, int>rg = *(--it);
			if(rg.second >= r[i]){
				int udp_cnt = cnt - calc(rg.first, rg.second) + calc(rg.first, l[i]) + calc(r[i], rg.second) + 1;
				if(udp_cnt >= k){
					cnt = udp_cnt;
					range.erase(it);
					range.insert(make_pair(rg.first, l[i]));
					range.insert(make_pair(r[i], rg.second));
					ans.push_back(i);
				}
			}
		}
		for(int& x : ans){
			cout << x << "\n";
		}
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	cin >> n >> k;
	for(int i = 1; i <= n; i++){
		cin >> l[i] >> r[i];
	}
	if(n <= 20){
		sub2::solve();
	}
	else{
		sub134::solve();
	}
}

컴파일 시 표준 에러 (stderr) 메시지

event2.cpp: In function 'int main()':
event2.cpp:111:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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