Submission #894735

#	Time	Username	Problem	Language	Result	Execution time	Memory
894735		Hando	Port Facility (JOI17_port_facility)	C++17	78 / 100	175 ms	71700 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 = 2e5 + 5;

vt <int> t[N << 2];
int idx[N << 2], par[N], d[N], a[N], b[N], mn[N], m[N << 1], vis[N];
 

inline int find(int u) {
    if (par[u] == u)
        return u;

    int p = find(par[u]);
    d[u] ^= d[par[u]];
    return par[u] = p;
}

inline bool unite(int u, int v, int w)  {
    int ru = find(u), rv = find(v);
    if (ru == rv) {
        return (d[u] ^ d[v]) == w;
    } else {
        d[ru] = w ^ d[u] ^ d[v];
        par[ru] = rv;
        return true;
    }

    assert(false);
    return false;
}

void build(int v, int tl, int tr) {
    idx[v] = 1;
    if (tl == tr) {
        if (m[tl]) {
            t[v].pub(m[tl]);
        }
        return;
    }

    int tm = (tl + tr) / 2;
    build(v * 2, tl, tm);
    build(v * 2 + 1, tm + 1, tr);
    merge(all(t[v * 2]), all(t[v * 2 + 1]), back_inserter(t[v]),
        [&](const int& i, const int& j) {
            return a[i] < a[j];
    });
}

bool query(int i, int v, int tl, int tr, int l, int r) {
    if (l <= tl && tr <= r) {
        if (len(t[v]) == 0 || a[t[v][0]] > a[i])
            return true;

        bool ret = 1;   
        ret &= unite(i, t[v][0], 1);
        while (idx[v] < len(t[v]) && a[t[v][idx[v]]] < a[i]) {
            ret &= unite(t[v][idx[v]], t[v][0], 0);
            idx[v]++;
        }
        return ret;
    } else {
        int tm = (tl + tr) / 2;
        if (r <= tm) return query(i, v * 2, tl, tm, l, r);
        else if (l > tm) return query(i, v * 2 + 1, tm + 1, tr, l, r);
        else return query(i, v * 2, tl, tm, l, r) & query(i, v * 2 + 1, tm + 1, tr, l, r);
    }

    assert(false);
    return false;
}
 
void solve() {
    int n; re(n);
    for (int i = 1; i <= n; ++i) {
        re(a[i], b[i]);
        par[i] = m[b[i]] = i;
    }
    
    build(1, 1, 2 * n);
    bool can = 1;
    for (int i = 1; i <= n; ++i)
        can &= query(i, 1, 1, 2 * n, a[i], b[i] - 1);

    if (!can) {
        return wr("0\n");
    }
    
    const int mod = 1e9 + 7;
    ll res = 1;
    vt <bool> vis(n + 1);
    for (int i = 1; i <= n; ++i) {
        if(vis[find(i)]) {
            continue;
        }
        vis[find(i)] = 1;
        res = (res * 2) % mod;
    }
    wr(res);
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    //Open("a");
 
    int t = 1;
    for(;t;t--) {
        solve();
    }
    
    return 0;
}

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