Submission #894461

#	Time	Username	Problem	Language	Result	Execution time	Memory
894461		Hando	Port Facility (JOI17_port_facility)	C++17	100 / 100	1734 ms	180612 KiB

port_facility

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

using namespace std;
using namespace __gnu_pbds;

#define ar array
#define vt vector
#define pq priority_queue
#define pu push
#define pub push_back
#define em emplace
#define emb emplace_back
#define mt make_tuple

#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()
#define allp(x, l, r) x.begin() + l, x.begin() + r
#define len(x) (int)x.size()
#define uniq(x) unique(all(x)), x.end()

using ll = long long;
using ld = long double;
using ull = unsigned long long;

template<class Fun> class y_combinator_result {
    Fun fun_;
public:
    template<class T> explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}
    template<class ...Args> decltype(auto) operator()(Args &&...args) { return fun_(std::ref(*this), std::forward<Args>(args)...); }
};
template<class Fun> decltype(auto) y_combinator(Fun &&fun) { return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun)); }

template <class T, size_t N>
void re(array <T, N>& x);
template <class T> 
void re(vt <T>& x);

template <class T> 
void re(T& x) {
    cin >> x;
}

template <class T, class... M> 
void re(T& x, M&... args) {
    re(x), re(args...);
}

template <class T> 
void re(vt <T>& x) {
    for(auto& it : x) re(it);
}

template <class T, size_t N>
void re(array <T, N>& x) {
    for(auto& it : x) re(it);
}

template <class T, size_t N>
void wr(const array <T, N>& x);
template <class T> 
void wr(const vt <T>& x);

template <class T> 
void wr(const T& x) {
    cout << x;
}

template <class T, class ...M>  
void wr(const T& x, const M&... args) {
    wr(x), wr(args...);
}

template <class T> 
void wr(const vt <T>& x) {
    for(auto it : x) wr(it, ' ');
}

template <class T, size_t N>
void wr(const array <T, N>& x) {
    for(auto it : x) wr(it, ' ');
}

template<class T, class... M>
auto mvt(size_t n, M&&... args) {
    if constexpr(sizeof...(args) == 1)
        return vector<T>(n, args...);
    else
        return vector(n, mvt<T>(args...));
}

void set_fixed(int p = 0) {
    cout << fixed << setprecision(p);
}

void set_scientific() {
    cout << scientific;
}

void Open(const string& name) {
#ifndef ONLINE_JUDGE
    (void)!freopen((name + ".in").c_str(), "r", stdin);
    (void)!freopen((name + ".out").c_str(), "w", stdout);
#endif
}

const int N = 1e6 + 5;
vt <int> adj[N];

int cnt;
int col[N];
int nxt[N], par[N], le[N], id[N << 1], a[N];


inline int find(int u) {
    return par[u] == u? u : par[u] = find(par[u]);
}

inline void add_edge(int u, int v) {
    adj[u].emb(v);
    adj[v].emb(u);
}

bool ok;

void dfs(int u, int c) {
    col[u] = c;
    for (auto& v : adj[u]) {
        if (!col[v]) {
            dfs(v, 3 - c);
        }

        if (col[v] == col[u]) {
            ok &= false;
        }
    }
}

void solve() {
    int n; re(n);
    for (int i = 1; i <= n; ++i) {
        int l, r; re(l, r);
        id[l] = id[r] = i;
    }

    for (int i = 1; i <= n; ++i)
        nxt[i] = par[i] = i;
    par[n + 1] = n + 1;


    for (int i = 1; i <= 2 * n; ++i) {
        int p = id[i];
        if (!le[p]) a[++cnt] = p, le[p] = cnt;
        else {
            int u = le[p];
            par[u] = find(u + 1);
            for (int j = par[u], k; j <= cnt; j = k) {
                add_edge(a[j], p);
                k = find(nxt[j] + 1);
                nxt[j] = cnt;
            }
        }
    }

    int cc = 0;
    for (int i = 1; i <= n; ++i)
        if (!col[i]) {
            ok = true;
            dfs(i, 1);
            if (ok) ++cc;
            else return wr("0\n");
        }

    const int mod = 1e9 + 7;
    ll res = 1;
    for (int i = 0; i < cc; ++i)
        res = (res * 2) % mod;

    wr(res);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    //Open("");

    int t = 1;
    for(;t;t--) {
        solve();
    }
    
    return 0;
}

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