Submission #914451

#	Time	Username	Problem	Language	Result	Execution time	Memory
914451		daoquanglinh2007	Port Facility (JOI17_port_facility)	C++17	0 / 100	7 ms	27224 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;

const int NM = 2e6, inf = 1e9+7, MOD = 1e9+7;

int N, r[NM+5], cnt = 0, ans = 1;
int suml[NM+5], sumr[NM+5], mn[NM+5], mn2[NM+5];

void update_sum(int sum[NM+5], int x){
	while (x <= NM){
		sum[x]++;
		x += x & (-x);
	}
}

void update_mn(int mn[NM+5], int x, int val){
	while (x <= NM){
		mn[x] = min(mn[x], val);
		x += x & (-x);
	}
}

int get_sum(int sum[NM+5], int x){
	int res = 0;
	while (x > 0){
		res += sum[x];
		x -= x & (-x);
	}
	return res;
}

int get_mn(int mn[NM+5], int x){
	int res = +inf;
	while (x > 0){
		res = min(res, mn[x]);
		x -= x & (-x);
	}
	return res;
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin >> N;
	for (int i = 1; i <= N; i++){
		int x, y; cin >> x >> y;
		r[x] = y;
	}
	for (int i = 1; i <= NM; i++) mn[i] = mn2[i] = +inf;
	for (int i = 2*N; i >= 1; i--){
		if (r[i] == 0) continue;
		cnt += get_sum(suml, r[i])-get_sum(sumr, r[i]);
		update_sum(suml, i);
		update_sum(sumr, r[i]);
		if (get_mn(mn2, 2*N-(r[i]+1)+1) <= r[i]){
			cout << 0;
			return 0;
		}
		int tmp = get_mn(mn, 2*N-(r[i]+1)+1);
		if (tmp <= r[i]){
			update_mn(mn2, 2*N-r[i]+1, tmp);
		}
		update_mn(mn, 2*N-r[i]+1, i);
	}
	for (int i = 1; i <= N-cnt; i++) ans = ans*2%MOD;
	cout << ans;
	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22