Submission #68309

#	Time	Username	Problem	Language	Result	Execution time	Memory
68309		reality	Port Facility (JOI17_port_facility)	C++17	100 / 100	2785 ms	585136 KiB

port_facility

#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define vii vector < pii >
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class P , class Q > ostream& operator<<(ostream& stream, pair < P , Q > v){ stream << "(" << v.fi << ',' << v.se << ")"; return stream;}
template < class T > ostream& operator<<(ostream& stream, const vector<T> v){ stream << "[ "; for (int i=0; i<(int)v.size(); i++) stream << v[i] << " "; stream << "]"; return stream;}
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
const int N = 2e6 + 5;
const int mod = 1e9 + 7;
int n;
int color[N];
vi g[N];
int f[N];
int get(int k) {
    return f[k] == k ? k : f[k] = get(f[k]);
} 
int main(void) {
    ios_base::sync_with_stdio(0);
    cin>>n;
    int ans = 1;
    vii e(n);
    for (auto & it : e)
        cin>>it.fi>>it.se;
    sort(all(e));
    for (int i = 0;i < n + n;++i)
        f[i] = i;
    map < int , int > M;
    for (int i = 0;i < n;++i) {
        auto l = M.lower_bound(e[i].fi);
        auto r = M.lower_bound(e[i].se);
        if (!M.empty()) {
            int lst;
            if (r != M.begin()) {
                --r;
                lst = get(r->se);
                ++r;
            } else {
                lst = get(r->se);
            }
            while (l != r) {
                f[get(l->se + n)] = get(i);
                f[get(l->se)] = get(i + n);
                if (get(l->se) == get(lst))
                    break;
                ++l;
            }
        }
        M[e[i].se] = i;
    }
    set < int > ss;
    for (int i = 0;i < n;++i)
        if (get(i) == get(i + n))
            ans = 0;
    for (int i = 0;i < n + n;++i)
            ss.insert(get(i));
    for (int i = 0;i < ss.size();i += 2)
        ans = (ans * 2) % mod;
    cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'int main()':
port_facility.cpp:67:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0;i < ss.size();i += 2)
                    ~~^~~~~~~~~~~

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