Submission #224297

#	Time	Username	Problem	Language	Result	Execution time	Memory
224297		osaaateiasavtnl	Port Facility (JOI17_port_facility)	C++14	0 / 100	20 ms	23808 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 = 1e6 + 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);
        }   
    }   
}   
 
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];
    for (int i = 1; i <= n; ++i) {
        for (int j = i + 1; j <= n; ++j) {
            if (intr(i, j) && !in(i, j) && !in(j, i)) {
                g[i].app(j);
                g[j].app(i);
            }   
        }   
    }   
    vector <ii> a;
    for (int i = 1; i <= n; ++i)
        a.app(mp(l[i], r[i]));
    sort(all(a));

    vector <int> s1, s2;
    s1.app(N); s2.app(N);
    for (auto e : a) {

        /*
        cout << "add " << e.f << ' ' << e.s << endl;
        for (auto e : s1)
            cout << e << ' ';
        cout << endl;
        for (auto e : s2)
            cout << e << ' ';
        cout << endl;
        */

        while (s1.back() < e.f)
            s1.pop_back();
        while (s2.back() < e.f)
            s2.pop_back();
        if (s1.back() < e.s && s2.back() < e.s) {
            cout << 0 << endl;
            exit(0);
        }
        else if (s1.back() < e.s) {
            s2.app(e.s);
        }   
        else if (s2.back() < e.s) {
            s1.app(e.s);
        }   
        else if (s1.back() < s2.back())
            s1.app(e.s);
        else
            s2.app(e.s);
    }   
    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: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22