제출 #135932

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
135932		gs14004	Arranging Tickets (JOI17_arranging_tickets)	C++17	45 / 100	12 ms	600 KiB

arranging_tickets

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5005;
using pi = pair<int, int>;
 
int n, m;
int a[MAXN], b[MAXN], c[MAXN];
 
bool Do(vector<int> l, vector<int> r, vector<pi> intv, int K){
	l[0] = r[0] = 1e9;
	for(int i=1; i<l.size(); i++) l[i] = min(l[i], l[i - 1]);
	for(int i=1; i<r.size(); i++) r[i] = min(r[i], r[i - 1]);
	l.push_back(0);
	r.push_back(0);
	sort(intv.begin(), intv.end());
	priority_queue<int, vector<int>, greater<int>> pq;
	int ptr = 0;
	vector<int> opt(r.size());
	for(int i=0; i + 1<l.size(); i++){
		while(ptr < intv.size() && intv[ptr].first <= i){
			pq.push(intv[ptr++].second);
		}
		while(l[i + 1] < K){
			if(pq.empty()) return 0;
			int nxt = pq.top(); pq.pop();
			opt[nxt]++;
			K--;
		}
	}
	for(int i=opt.size()-2; i>=0; i--) opt[i] += opt[i + 1];
	for(int i=0; i<r.size(); i++){
		if(opt[i] > r[i]) return false;
	}
	return true;
}

int cnt[MAXN];
bool trial(int x){
	int maxpos = max_element(cnt + 1, cnt + n + 1) - cnt;
	int mx = cnt[maxpos];
	if(mx <= x) return true;
	for(int i=mx-x; i<=mx-x+1 && i<=m; i++){
		vector<int> surp(n - 1);
		for(int j=0; j<n-1; j++){
			surp[j] = x + i - cnt[j + 1];
			surp[j] /= 2;
		}
		// number of reversal
		int j = maxpos;
		assert(j - 1 < surp.size() && surp[j - 1] == 0);
		vector<pi> intv;
		for(int k=0; k<m; k++){
			if(a[k] <= j && b[k] > j){
				intv.emplace_back(a[k] - 1, n - b[k]);
			}
		}
		vector<int> l = {0};
		vector<int> r = {0};
		for(int k=0; k<j-1; k++) l.push_back(surp[k]);
		for(int k=n-2; k>=j; k--) r.push_back(surp[k]);
		if(Do(l, r, intv, i)) return true;
	}
	return false;
}
 
int main(){
	cin >> n >> m;
	for(int i=0; i<m; i++){
		cin >> a[i] >> b[i] >> c[i];
		if(a[i] > b[i]) swap(a[i], b[i]);
		cnt[a[i]]++;
		cnt[b[i]]--;
	}
	for(int i=1; i<=n; i++) cnt[i] += cnt[i-1];
	int s = 0, e = 10000;
	while(s != e){
		int m = (s+e)/2;
		if(trial(m)) e = m;
		else s = m+1;
	}
	cout << s << endl;
}

• Subtask 1: 10 / 10
• Subtask 2: 35 / 35
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 15