Submission #27884

#	Time	Username	Problem	Language	Result	Execution time	Memory
27884		suhgyuho_william	Port Facility (JOI17_port_facility)	C++14	0 / 100	0 ms	26436 KiB

port_facility

#include <bits/stdc++.h>

#define lld long long
#define pii pair<int,int>
#define pll pair<lld,lld>
#define pb push_back
#define next nextt
#define left leftt
#define right rightt
#define Inf 1000000000
#define Linf 1000000000000000000LL
#define Mod 1000000007LL

using namespace std;

int N; lld ans,inv;
struct data{
	int x,y;
	bool operator < (const data &cmp) const{
		if(x != cmp.x) return x < cmp.x;
		return y < cmp.y;
	}
}a[2000002],in[1000002];
bool check[1000002];

void dfs(int x){
	check[x] = true;
	for(int i=x+1; i<=N; i++){
		if(check[i]) continue;
		if(a[x].x < a[i].x && a[i].x < a[x].y && a[x].y < a[i].y) dfs(i);
	}
}

int main(){
	scanf("%d",&N); ans = 1;
	for(int i=1; i<=N; i++){
		scanf("%d %d",&a[i].x,&a[i].y);
		a[i+N].x = a[i].y; a[i+N].y = -a[i].y;
		in[i].x = a[i].x; in[i].y = a[i].y;
	}
	sort(a+1,a+N*2+1);
{
	vector<int> t1,t2;
	for(int i=1; i<=N*2; i++){
		if(a[i].y > 0){
			if(t1.size() == 0) t1.pb(a[i].y);
			else if(t2.size() == 0) t2.pb(a[i].y);
			else if(t1.back() < t2.back() && t1.back() > a[i].y) t1.pb(a[i].y);
			else if(t2.back() < t1.back() && t2.back() > a[i].y) t2.pb(a[i].y);
			else if(t1.back() > a[i].y) t1.pb(a[i].y);
			else if(t2.back() > a[i].y) t2.pb(a[i].y);
			else{
				puts("0");
				return 0;
			}
		}else{
			if(t1.size() != 0 && t1.back() == -a[i].y) t1.pop_back();
			else t2.pop_back();
		}
	}
}
	for(int i=1; i<=N; i++) a[i] = in[i];
	sort(a+1,a+N+1);
	for(int i=1; i<=N; i++){
		if(check[i]) continue;
		dfs(i);
		ans *= 2; ans %= Mod;
	}
	printf("%lld\n",ans);

	return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'int main()':
port_facility.cpp:35:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&N); ans = 1;
                ^
port_facility.cpp:37:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&a[i].x,&a[i].y);
                                 ^

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