Submission #995017

#	Time	Username	Problem	Language	Result	Execution time	Memory
995017		Sharky	Port Facility (JOI17_port_facility)	C++17	0 / 100	0 ms	344 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define int long long
const int mod = 1e9+7;

bool overlap(ll l1, ll r1, ll l2, ll r2){
    return (l1 < l2 && l2 < r1 && r1 < r2);
}

bool ate(ll l1, ll r1, ll l2, ll r2) {
    return (l2 < l1 && l1 < r1 && r1 < r2);
}

int p[4005], sz[4005];

int find(int u) {
    return p[u] == u ? u : p[u] = find(p[u]);
}

void merge(int u, int v) {
    u = find(u), v = find(v);
    if (u == v) return;
    if (sz[u] < sz[v]) swap(u, v);
    p[v] = u;
    sz[u] += sz[v];
}

int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0);
    // freopen("debug.txt", "w", stdout);
    int n;
    cin >> n;
    int m = 2 * n;
    vector<int> a(m + 1, 0);
    for (int i = 1; i <= n; i++) {
        int lll, rrr;
        cin >> lll >> rrr;
        a[lll] = a[rrr] = i;
    }
    // for (int i = 1; i <= m; i++) cin >> a[i];
    vector<int> L(n+1, -1), R(n+1, -1);
    for (int i = 1; i <= m; i++) {
        if (L[a[i]] == -1) L[a[i]] = i;
        else if (R[a[i]] == -1) R[a[i]] = i;
    }
    vector<int> I(n+1), O(n+1);
    for (int i = 1; i <= n; i++) I[i] = i;
    for (int i = 1; i <= n; i++) O[i] = i + 2 * n;
    for (int i = 0; i < 4005; i++) p[i] = i, sz[i] = 1;
    vector<int> cnt(2 * n+1, 0);
    vector<int> e(n+1, 0);
    for (int i = 1; i <= m; i++) {
        if (!e[a[i]]) cnt[i] = cnt[i-1]+1, e[a[i]] = 1;
        else cnt[i] = cnt[i-1] - 1, e[a[i]] = 0;
    }
    vector<int> far(m+1, 0);
    for (int i = 1; i <= m; i++) far[i] = max(far[i-1], R[a[i]]);
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(i!=j){
              if(overlap(L[i],R[i],L[j],R[j])) {
                merge(I[j], O[i] + n);
                merge(I[j] + n, O[i]);
                // cout << far[L[i] - 1] << ' ' << R[i] << '\n';
                if (far[L[i]-1] >= R[i]) {
                    merge(I[i], I[j] + n);
                    merge(I[i] + n, I[j]);
                    // cout << "I " << i << " diff with " << "I " << j << '\n';
                }
                // cout << "I " << j << " diff with " << "O " << i << '\n';
              }
              if(ate(L[i],R[i],L[j],R[j])){
                merge(I[i], O[i]);
                merge(I[i] + n, O[i] + n);
                // cout << "I " << i << " same with " << "O " << i << '\n';
              }
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        vector<bool> siu(n+1, 1);
        for (int j = L[i] + 1; j <= R[i] - 1; j++) {
            if (j == R[a[j]]) siu[a[j]] = true;
            else siu[a[j]] = false;
        }
        vector<int> meisiu;
        for (int j = 1; j <= n; j++) if (!siu[j]) {
            meisiu.push_back(j);
        }
        for (int j = 1; j < meisiu.size(); j++) {
            int prv = meisiu[j - 1], cur = meisiu[j];
            merge(I[prv], I[cur]);
            // cout << "I " << prv << " same with " << "I " << cur << '\n';
            merge(I[prv] + n, I[cur] + n);
        }
    }
    for(int i=1; i<= n; i++) {
        if (find(I[i]) == find(I[i] + n)) {
            cout << "0\n";
            return 0;
        }
        if (find(O[i]) == find(O[i] + n)) {
            cout << "0\n";
            return 0;
        }
    }
    set<int> disc;
    for (int i = 1; i <= n; i++) {
        // disc.insert(find(I[i]));
        // disc.insert(find(O[i]));
        // cout << find(I[i]) << ' ' << find(O[i]) << '\n';
        int x = find(I[i]), y = find(O[i]);
        if (n < x && x <= 2 * n) x -= n;
        if (3 * n < x && x <= 4 * n) x -= n;
        if (n < y && y <= 2 * n) y -= n;
        if (3 * n < y && y <= 4 * n) y -= n;
        disc.insert(x);
        disc.insert(y);
    }
    ll ans=1;
    for(int i=1;i<=disc.size();i++){
        ans*=2;
        ans%=mod;
    }
    cout<<ans<<'\n';
}

Compilation message (stderr)

port_facility.cpp: In function 'int32_t main()':
port_facility.cpp:92:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |         for (int j = 1; j < meisiu.size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~
port_facility.cpp:123:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::set<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |     for(int i=1;i<=disc.size();i++){
      |                 ~^~~~~~~~~~~~~

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