Submission #1062420

#TimeUsernameProblemLanguageResultExecution timeMemory
106242012345678Port Facility (JOI17_port_facility)C++17
100 / 100
2551 ms228980 KiB
#include <bits/stdc++.h>

using namespace std;

const int nx=2e6+5, mod=1e9+7;

int n, l[nx], r[nx], res=1, cnt, c[nx], f, vs[nx];
vector<int> d[nx];
pair<int, int> v[2*nx];

struct mnsegtree
{
    pair<int, int> d[4*nx];
    void update(int l, int r, int i, int idx, int vl, int id)
    {
        if (idx<l||r<idx) return;
        if (l==r) return d[i]={vl, id}, void();
        int md=(l+r)/2;
        update(l, md, 2*i, idx, vl, id);
        update(md+1, r, 2*i+1, idx, vl, id);
        d[i]=min(d[2*i], d[2*i+1]);
    }
    pair<int, int> query(int l, int r, int i, int ql, int qr)
    {
        //cout<<"debug "<<l<<' '<<r<<' '<<ql<<' '<<qr<<'\n';
        if (qr<l||r<ql||qr<ql) return {1e9, 1e9};
        if (ql<=l&&r<=qr) return d[i];
        int md=(l+r)/2;
        return min(query(l, md, 2*i, ql, qr), query(md+1, r, 2*i+1, ql, qr));
    }
} smn;

struct mxsegtree
{
    pair<int, int> d[4*nx];
    void update(int l, int r, int i, int idx, int vl, int id)
    {
        if (idx<l||r<idx) return;
        if (l==r) return d[i]={vl, id}, void();
        int md=(l+r)/2;
        update(l, md, 2*i, idx, vl, id);
        update(md+1, r, 2*i+1, idx, vl, id);
        d[i]=max(d[2*i], d[2*i+1]);
    }
    pair<int, int> query(int l, int r, int i, int ql, int qr)
    {
        if (qr<l||r<ql||qr<ql) return {-1e9, -1e9};
        if (ql<=l&&r<=qr) return d[i];
        int md=(l+r)/2;
        return max(query(l, md, 2*i, ql, qr), query(md+1, r, 2*i+1, ql, qr));
    }
} smx;

void dfs(int u)
{
    vs[u]=1;
    for (auto v:d[u])
    {
        if (vs[v])
        {
            if (c[v]==c[u]) f=1;
            continue;
        }
        c[v]=!c[u];
        dfs(v);
    }
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=1; i<=n; i++) 
    {
        cin>>l[i]>>r[i];
        smn.update(1, 2*n, 1, l[i], r[i], i);
        smx.update(1, 2*n, 1, l[i], r[i], i);
        smn.update(1, 2*n, 1, r[i], l[i], i);
        smx.update(1, 2*n, 1, r[i], l[i], i);
    }
    for (int i=1; i<=n; i++)
    {
        auto mn=smn.query(1, 2*n, 1, l[i]+1, r[i]-1), mx=smx.query(1, 2*n, 1, l[i]+1, r[i]-1);
        //cout<<"mn "<<mn.first<<' '<<mn.second<<'\n';
        if (mn.first<l[i]) d[i].push_back(mn.second), d[mn.second].push_back(i);
        if (mx.first>r[i] )d[i].push_back(mx.second), d[mx.second].push_back(i);
    }
    for (int i=1; i<=n; i++) if (!vs[i]) dfs(i), res=(res*2)%mod;
    if (f) cout<<0;
    else cout<<res;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...