Submission #991924

#	Time	Username	Problem	Language	Result	Execution time	Memory
991924		onbert	Passport (JOI23_passport)	C++17	16 / 100	6 ms	6848 KiB

passport

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 2e5 + 20, m = 450, INF = 1e9;
int Rcost[maxn];
pair<int,int> Lcost[maxn];
bool cmp(int a, int b) {
    return Lcost[a].second < Lcost[b].second;
}

signed main() {
    ios::sync_with_stdio(0); cin.tie(0);
    int n;
    cin >> n;
    pair<int,int> a[n+1];
    vector<pair<int,int>> Lpos[m], Rpos[m];
    vector<pair<int,int>> lpos[m], rpos[m];
    for (int i=1;i<=n;i++) {
        cin >> a[i].first >> a[i].second;
        if (i!=1) {
            Lpos[a[i].first/m].push_back({a[i].second, i});
            lpos[a[i].first].push_back({a[i].second, i});
        }
        if (i!=n) {
            Rpos[a[i].second/m].push_back({a[i].first, i});
            rpos[a[i].second].push_back({a[i].first, i});
        }
    }


    for (int i=0;i<m;i++) sort(Rpos[i].rbegin(), Rpos[i].rend());
    for (int i=1;i<=n;i++) sort(rpos[i].rbegin(), rpos[i].rend());
    bool vis[n+1];
    for (int i=1;i<=n;i++) vis[i] = false;
    vis[n] = true;
    vector<int> from = {n}, to;
    int Rcost[n+1];
    for (int i=1;i<=n;i++) Rcost[i] = INF;
    for (int cost=-1; from.size()>0; cost++) {
        for (int u:from) Rcost[u] = max(cost, (int)0);
        for (int u:from) {
            for (int R=m-1;R*m>=u;R--) {
                while (Rpos[R].size()>0 && Rpos[R].back().first<=u) {
                    int v = Rpos[R].back().second;
                    if (!vis[v]) to.push_back(v);
                    vis[v] = true;
                    Rpos[R].pop_back();
                }
            }
            int r = (u+m-1)/m*m - 1;
            for (;r>=u;r--) {
                    while (rpos[r].size()>0 && rpos[r].back().first<=u) {
                    int v = rpos[r].back().second;
                    if (!vis[v]) to.push_back(v);
                    vis[v] = true;
                    rpos[r].pop_back();
                }
            }
        }
        from.clear();
        swap(to, from);
    }

    for (int i=0;i<m;i++) sort(Lpos[i].begin(), Lpos[i].end());
    for (int i=0;i<=n;i++) sort(lpos[i].begin(), lpos[i].end());
    for (int i=1;i<=n;i++) vis[i] = false;
    vis[1] = true;
    from = {1};
    for (int i=1;i<=n;i++) Lcost[i] = {INF, INF};
    Lcost[1].second = Rcost[1] + 1;
    for (int cost=0; from.size()>0; cost++) {
        sort(from.begin(), from.end(), cmp);
        for (int u:from) Lcost[u].first = cost;
        for (int u:from) {
            for (int L=0;(L+1)*m-1<=u;L++) {
                while (Lpos[L].size()>0 && Lpos[L].back().first>=u) {
                    int v = Lpos[L].back().second;
                    if (!vis[v]) {
                        to.push_back(v);
                        Lcost[v].second = min(Rcost[v], Lcost[u].second);
                    }
                    vis[v] = true;
                    Lpos[L].pop_back();
                }
            }
            int l = u/m*m;
            for (;l<=u;l++) {
                    while (lpos[l].size()>0 && lpos[l].back().first>=u) {
                    int v = lpos[l].back().second;
                    if (!vis[v]) {
                        to.push_back(v);
                        Lcost[v].second = min(Rcost[v], Lcost[u].second);
                    }
                    vis[v] = true;
                    lpos[l].pop_back();
                }
            }
        }
        from.clear();
        swap(to, from);
    }
    
    int q;
    cin >> q;
    for (int i=0;i<q;i++) {
        int pos;
        cin >> pos;
        if (Lcost[pos].first>=INF || Lcost[pos].second>=INF) cout << "-1\n";
        else cout << Lcost[pos].first + Lcost[pos].second << "\n";
    }
}

• Subtask 1: 0 / 6
• Subtask 2: 16 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 8
• Subtask 5: 0 / 46