| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 752923 | bgnbvnbv | Port Facility (JOI17_port_facility) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define ll long long
#define pll pair<ll, ll>
#define pii pair<ll, pll>
#define pb push_back
#define fi first
#define se second
using namespace std;
const int N = 2e6+5;
const ll mod = 1e9 + 7;
const int base = 40;
ll n, m, k, t, a[N], b[N], tong, dp[N], lab[N], ans;
char c;
vector<ll> adj[N], kq;
pll p[N];
ll pw(ll k, ll n)
{
ll total = 1;
for(; n; n >>= 1)
{
if(n & 1)total = total * k % mod;
k = k * k % mod;
}
return total;
}
ll findp(ll u)
{
return lab[u] < 0 ? u : lab[u] = findp(lab[u]);
}
void hop(ll u, ll v)
{
if(lab[u] > lab[v])swap(u, v);
lab[u] += lab[v];
lab[v] = u;
}
void sol()
{
cin >> n;
fill_n(lab, n*2+4, -1);
for(int i = 1; i <= n; i ++)
{
cin >> p[i].fi >> p[i].se;
}
sort(p+1, p+1+n);
set<pll> st;
for(int i = 1; i <= n; i ++)
{
auto l = st.lower_bound({p[i].fi, 0ll}), r = st.upper_bound({p[i].se, n*2+1});
if(l != st.end() && r != st.begin() && (*l).fi < p[i].se)
{
r = prev(r);
while(true)
{
pll x = *l;
ll u = findp(i), v = findp(x.se+n);
if(u != v)hop(u, v);
u = findp(i+n), v = findp(x.se);
if(u != v)hop(u, v);
if(l==rbreak;
++l;
}
}
st.insert({p[i].se, i});
}
for(int i = 1; i <= n*2; i ++)
{
if(i <= n && findp(i) == findp(i+n))
{
cout << 0;
return;
}
if(lab[i] < 0)++ans;
}
cout << pw(2, ans/2);
}
int main()
{
cin.tie(0);
cout.tie(0);
ios_base::sync_with_stdio(0);
int test = 1;
//cin >> test;
while (test-- > 0)
sol();
return 0;
}