Submission #57667

#	Time	Username	Problem	Language	Result	Execution time	Memory
57667		Benq	Port Facility (JOI17_port_facility)	C++14	100 / 100	3491 ms	752648 KiB

port_facility

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 1000001;

int N;
pi par[MX];
vi rap[MX][2];
map<int,int> M[MX];
vpi p;
map<int,int> m;

void input() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N; p.resize(N);
    m.clear();
    F0R(i,N) {
        F0R(j,2) rap[i][j].clear();
        M[i].clear();
    }
    F0R(i,N) {
        cin >> p[i].f >> p[i].s;
    }
    sort(all(p));
    F0R(i,N) {
        par[i] = {i,0};
        rap[i][0].pb(i);
        M[i][p[i].s] = i;
    }
}

void unite(int a, int b) {
    // cout << "AH " << a << " " << b << "\n";
    if (par[a].f == par[b].f) {
        if (par[a].s == par[b].s) {
            cout << 0;
            exit(0);
        }
        return;
    }
    bool eq = (par[a].s == par[b].s); 
    a = par[a].f, b = par[b].f;
    if (sz(rap[a][0])+sz(rap[a][1]) < sz(rap[b][0])+sz(rap[b][1])) swap(a,b);
    
    F0R(j,2) for (int i: rap[b][j]) {
        par[i] = {a,j^eq};
        rap[a][j^eq].pb(i);
        M[a][p[i].s] = i;
    }
    F0R(j,2) rap[b][j].clear();
    M[b].clear();
}

void del(int mn) {
    int x = par[m.begin()->s].f;
    m.erase(m.begin());
    auto IT = M[x].lb(mn);
    if (IT == M[x].end()) return;
    // cout << "OOPS " << x << " " << IT->f << " " << IT->s << "\n";
    m[IT->f] = IT->s;
}

void check(vi v) {
    sort(all(v));
    /*for (int i: v) cout << i << " * ";
    cout << "BAD\n";
    for (int i: v) cout << p[i].f << " " << p[i].s << " | ";
    cout << "\n";*/
    set<int> z;
    for (int i: v) {
        while (sz(z) && *z.begin() < p[i].f) z.erase(z.begin());
        if (sz(z) && *z.begin() < p[i].s) {
            // cout << "\nAH " << i << " " << p[i].f << " " << p[i].s << " " << *z.begin() << " " << sz(z) << "\n";
            cout << 0;
            exit(0);
        }
        z.insert(p[i].s);
    }
}

void solve() {
    input();
    F0R(i,sz(p)) {
        while (sz(m) && m.begin()->f < p[i].f) del(p[i].f);
        vi to;
        for (auto a: m) {
            if (a.f < p[i].s) to.pb(a.s);
            else break;
        }
        // for (int j: to) cout << p[j].f << " " << p[j].s << " " << j << " " << i << "\n";
        for (int j: to) {
            m.erase(p[j].s);
            unite(j,i);
        }
        to.pb(i);
        m[p[to.front()].s] = to.front();
    }
    int ans = 1;
    F0R(i,N) if (par[i].f == i) {
        ans = 2*ans%MOD;
        check(rap[i][0]);
        check(rap[i][1]);
    }
    cout << ans << "\n";
}

int main() {
    F0R(i,1) solve();
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

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