Submission #224283

#	Time	Username	Problem	Language	Result	Execution time	Memory
224283		osaaateiasavtnl	Port Facility (JOI17_port_facility)	C++14	10 / 100	86 ms	79740 KiB

port_facility

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair <int, int>
#define app push_back
#define all(a) a.begin(), a.end()
#define bp __builtin_popcount
#define ll long long
#define mp make_pair
#define f first
#define s second
#define Time (double)clock()/CLOCKS_PER_SEC

const int N = 2e6 + 7, MOD = 1000 * 1000 * 1000 + 7;
vector <int> g[N];
int l[N], r[N];
bool intr(int i, int j) {
    int a = max(l[i], l[j]);
    int b = min(r[i], r[j]);
    return a <= b;
}   
bool in(int i, int j) {
    return l[j] <= l[i] && r[i] <= r[j];
}   
bool used[N];
void dfs(int u) {
    used[u] = 1;
    for (int v : g[u]) {
        if (!used[v]) 
            dfs(v);
    }   
}   

bool edge(int i, int j) {
    return intr(i, j) && !in(i, j) && !in(j, i);
}   

int rin[N], lin[N];
int who[N];
bool comp(ii a, ii b) {
    return a.s > b.s;
}   

signed main() {
    #ifdef HOME
    freopen("input.txt", "r", stdin);
    #else
    #define endl '\n'
    ios_base::sync_with_stdio(0); cin.tie(0);
    #endif
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> l[i] >> r[i];
        who[l[i]] = who[r[i]] = i;
    }
    for (int i = 1; i <= n; ++i) {
        for (int j = i + 1; j <= n; ++j) {
            if (edge(i, j)) {
                g[i].app(j);
                g[j].app(i);
            }   
        }   
    }
    
    /*
    for (int i = 1; i <= n; ++i) {
        for (int j = i + 1; j <= n; ++j) {
            for (int k = j + 1; k <= n; ++k) {
                if (edge(i, j) && edge(j, k) && edge(i, k)) {
                    cout << 0 << endl;
                    exit(0);
                }   
            }   
        }   
    }   
    */

    vector <ii> a;
    {
    for (int i = 1; i <= n; ++i) 
        a.app(mp(l[i], r[i]));
    sort(all(a));
    set <int> ms;
    for (auto e : a) {
        int i = who[e.f];
        auto t = ms.upper_bound(e.s);
        if (t == ms.begin()) 
            rin[i] = -1;
        else {
            --t;
            rin[i] = *t;
        }   
        ms.insert(e.s);            
    }   
    }

    {
    sort(all(a), comp);        
    set <int> ms;
    for (auto e : a) {
        int i = who[e.f];
        auto t = ms.lower_bound(e.f);
        if (t == ms.end())
            lin[i] = N;
        else
            lin[i] = *t;
        ms.insert(e.f);
    }   
    }

    for (int i = 1; i <= n; ++i) {
        if (lin[i] < rin[i]) {
            cout << 0 << endl;
            exit(0);
        }   
    }   

    int comp = 0;
    for (int i = 1; i <= n; ++i) {
        if (!used[i]) {
            dfs(i);
            ++comp;
        }   
    }   
    int ans = 1;
    for (int i = 0; i < comp; ++i)
        ans = (ans << 1) % MOD;
    cout << ans << endl;
}

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