Submission #197782

#	Time	Username	Problem	Language	Result	Execution time	Memory
197782		arnold518	Port Facility (JOI17_port_facility)	C++14	22 / 100	4422 ms	1048580 KiB

port_facility

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 1e6;
const ll MOD = 1e9+7;

struct Data
{
	int L, R;
};

int N, col[MAXN+10];
Data A[MAXN+10];
vector<int> adj[MAXN+10];

bool vis[MAXN+10];
vector<pii> tree[MAXN*8+10];

void update(int node, int tl, int tr, int l, int r, int k)
{
	tree[node].push_back(pii(l, k));
	if(tl==tr) return;
	int mid=tl+tr>>1;
	if(r<=mid) update(node*2, tl, mid, l, r, k);
	else update(node*2+1, mid+1, tr, l, r, k);
}	

void query(int node, int tl, int tr, int l, int r, int k)
{
	int i, j;
	if(r<tl || tr<l) return;
	if(l<=tl && tr<=r)
	{
		for(i=tree[node].size()-1; i>=0; i--)
		{
			if(tree[node][i].first>=l) break;
			adj[k].push_back(tree[node][i].second);
			adj[tree[node][i].second].push_back(k);
		}
		return;
	}
	int mid=tl+tr>>1;
	query(node*2, tl, mid, l, r, k);
	query(node*2+1, mid+1, tr, l, r, k);
}

void dfs(int now, int c)
{
	col[now]=c;
	for(auto nxt : adj[now]) if(col[nxt]==0) dfs(nxt, 3-c);
}

int main()
{
	int i, j;
	scanf("%d", &N);
	for(i=1; i<=N; i++) scanf("%d%d", &A[i].L, &A[i].R);

	sort(A+1, A+N+1, [&](const Data &p, const Data &q) { return p.L<q.L; });

	for(i=N; i>=1; i--) update(1, 1, 2*N, A[i].L, A[i].R, i);
	for(i=1; i<=N; i++) query(1, 1, 2*N, A[i].L, A[i].R, i);

	int cnt=0;
	for(i=1; i<=N; i++) if(col[i]==0) dfs(i, 1), cnt++;

	vector<int> S[3];
	vector<pii> todo;
	for(i=1; i<=N; i++) todo.push_back({A[i].L, i}), todo.push_back({A[i].R, i+N});
	sort(todo.begin(), todo.end());

	for(auto it : todo)
	{
		if(it.second>N)
		{
			if(!S[1].empty() && S[1].back()==it.second-N) S[1].pop_back();
			else if(!S[2].empty() && S[2].back()==it.second-N) S[2].pop_back();
			else return !printf("0");
		}
		else
		{
			S[col[it.second]].push_back(it.second);
		}
	}

	ll ans=1;
	for(i=1; i<=cnt; i++) ans=ans*2%MOD;
	printf("%lld", ans);
}

Compilation message (stderr)

port_facility.cpp: In function 'void update(int, int, int, int, int, int)':
port_facility.cpp:27:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=tl+tr>>1;
          ~~^~~
port_facility.cpp: In function 'void query(int, int, int, int, int, int)':
port_facility.cpp:46:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=tl+tr>>1;
          ~~^~~
port_facility.cpp:34:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j;
         ^
port_facility.cpp: In function 'int main()':
port_facility.cpp:59:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j;
         ^
port_facility.cpp:60:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
port_facility.cpp:61:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1; i<=N; i++) scanf("%d%d", &A[i].L, &A[i].R);
                      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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