Submission #43726

#	Time	Username	Problem	Language	Result	Execution time	Memory
43726		MatheusLealV	Port Facility (JOI17_port_facility)	C++14	10 / 100	900 ms	24440 KiB

port_facility

#include <bits/stdc++.h>
#define N 3001
#define mod (1000000000 + 7)
#define f first
#define s second
using namespace std;
typedef pair<int, int> pii;

int n, ans, block[N][N];

pii v[N];

bool intersect(int i, int j)
{
	if(v[j].f < v[i].f) swap(i, j);

	if(v[i].f <= v[j].f && v[j].s <= v[i].s) return false;

	if(v[i].f < v[j].f && v[j].f < v[i].s) return true;

	return false;
}

bool check(int mask)
{
	vector<int> A, B;

	for(int i = 0; i < n; i++)
	{
		if(mask & (1<<i)) A.push_back(i + 1);

		else B.push_back(i + 1);
	}

	for(int i = 0; i < A.size(); i++)
	{
		for(int j = 0; j < A.size(); j++)
		{
			if(block[ A[i] ][ A[j] ]) return false;
		}
	}

	A = B;

	for(int i = 0; i < A.size(); i++)
	{
		for(int j = 0; j < A.size(); j++)
		{
			if(block[A[i]][A[j]]) return false;
		}
	}

	return true;
}

void ptr(int mask)
{
	for(int i = n - 1; i >= 0; i--) cout<< (mask & (1<<i) ? 1 : 0);

	cout<<"\n\n";
}

int main()
{
	ios::sync_with_stdio(false); cin.tie(0);

	cin>>n;

	for(int i = 1; i <= n; i++) cin>>v[i].f>>v[i].s;

	for(int i = 1; i <= n; i++)
	{
		for(int j = 1; j <= n; j++)
		{
			block[i][j] = intersect(i, j);
		}
	}

	for(int mask = 0; mask < (1<<n); mask ++) if(check(mask)) ans = (ans + 1)%mod;//ptr(mask);

	cout<<ans<<"\n";

}

Compilation message (stderr)

port_facility.cpp: In function 'bool check(int)':
port_facility.cpp:35:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < A.size(); i++)
                   ^
port_facility.cpp:37:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 0; j < A.size(); j++)
                    ^
port_facility.cpp:45:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < A.size(); i++)
                   ^
port_facility.cpp:47:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 0; j < A.size(); j++)
                    ^

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