Submission #385111

#	Time	Username	Problem	Language	Result	Execution time	Memory
385111		ACmachine	Port Facility (JOI17_port_facility)	C++17	22 / 100	6072 ms	16492 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)

const double EPS = 1e-9;
const int MOD = 1e9+7;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

void DBG(){cout << "]" << endl;}
template<typename T, typename ...U> void DBG(const T& head, const U... args){ cout << head << "; "; DBG(args...); }
#define dbg(...) cout << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__);
#define chk() cout << "Check at line(" << __LINE__ << ") hit." << endl;

template<class T, unsigned int U>
ostream& operator<<(ostream& out, const array<T, U> &v){out << "[";  REP(i, U) out << v[i] << ", ";  out << "]"; return out;}
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}

template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }

const int mod = (int)1e9+7;
struct Mint{
    int val;
    Mint(){ val = 0; }
    Mint(long long v){
        val = (-mod <= v && v < mod) ? v : v%mod;
        if(val < 0) val+= mod;
    }
    // operators
    Mint operator-(){return Mint(-val);}
    Mint& operator+=(const Mint& other){ val+=other.val; if(val >= mod) val-=mod; return *this;}
    Mint& operator-=(const Mint& other){ val-=other.val; if(val < 0) val+=mod; return *this;}
    Mint& operator*=(const Mint& other){ val=((long long)val*other.val)%mod; return *this;}
    friend Mint binpow(Mint a, long long p){
        Mint res(1);
        while(p > 0){
            if(p&1) res*=a; a*=a; p>>=1;
        }
        return res;
    }
    friend Mint inv(Mint a){ return binpow(a, mod-2); }
    Mint& operator/=(const Mint &other){ return (*this)*=inv(other);}

    friend Mint operator+(Mint a, const Mint& b){ return a+=b; }
    friend Mint operator-(Mint a, const Mint& b){ return a-=b; }
    friend Mint operator*(Mint a, const Mint& b){ return a*=b; }
    friend Mint operator/(Mint a, const Mint& b){ return a/=b; }

    bool operator==(const Mint &other){return val == other.val;}
    bool operator!=(const Mint &other){return val != other.val;}
    bool operator<(const Mint &other){return val < other.val;}
    // io
    friend ostream& operator<<(ostream &out, Mint &a){ return out << a.val; }
};


int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
    int n; cin >> n;
    vector<int> a(n);
    vector<int> b(n);
    REP(i, n){
        cin >> a[i] >> b[i];
    }
    auto isect = [](int a, int b, int c, int d) -> bool{
        if(b < c || d < a) return false;
        if((a > c && b < d) || (c > a && d < b)) return false;
        return true;
    };
    bool can = true;
    vector<vector<int>> g(n);
    REP(i, n){
        REP(j, i){
            if(isect(a[i], b[i], a[j], b[j])){
                g[i].pb(j);
                g[j].pb(i);
            }
        }
    }
    vector<int> dist(n, -1);
    auto bfs = [&](int s){
        dist[s] = 0;
        queue<int> q;
        q.push(s);
        while(!q.empty()){
            int v = q.front();
            q.pop();
            for(int x : g[v]){
                if(dist[x] == -1){
                    dist[x] = dist[v] + 1;
                    q.push(x);
                }
                else{
                    if((dist[x] % 2) == (dist[v] % 2))
                        can = false;
                }
            }
        }
    };
    int comp = 0;
    REP(i, n){
        if(dist[i] == -1){
            comp++;
            bfs(i);
        }
    }
    if(!can){
        cout << "0\n";
    }
    else{
        Mint ans = binpow(Mint(2), comp);
        cout << ans << "\n";
    }
    return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'Mint binpow(Mint, long long int)':
port_facility.cpp:73:13: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   73 |             if(p&1) res*=a; a*=a; p>>=1;
      |             ^~
port_facility.cpp:73:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   73 |             if(p&1) res*=a; a*=a; p>>=1;
      |                             ^

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