Submission #936733

#	Time	Username	Problem	Language	Result	Execution time	Memory
936733		velislavgarkov	Passport (JOI23_passport)	C++14	100 / 100	786 ms	92776 KiB

passport

#include <iostream>
#include <vector>
#include <queue>
#include <cstring>
using namespace std;
#define endl '\n'
const int MAXN=2e5+10;
vector <pair <int,int> > v[5*MAXN];
int l[MAXN], r[MAXN], c[MAXN];
int dist[5*MAXN];
priority_queue <pair <int,int> > q;
int n;
void build(int node, int l, int r) {
    if (l==r) {
        v[4*n+l].push_back({node,0});
        return;
    }
    int mid=(l+r)/2;
    v[node*2].push_back({node,0});
    v[node*2+1].push_back({node,0});
    build(node*2,l,mid);
    build(node*2+1,mid+1,r);
}
void find_passports(int node, int l, int r, int ql, int qr, int ver) {
    if (ql>r || qr<l) return;
    if (l>=ql && r<=qr) {
        v[node].push_back({ver,1});
        return;
    }
    int mid=(l+r)/2;
    find_passports(node*2,l,mid,ql,qr,ver);
    find_passports(node*2+1,mid+1,r,ql,qr,ver);
}
void dejkstra(int start) {
    memset(dist,-1,sizeof(dist));
    dist[start]=0;
    q.push({0,start});
    while (!q.empty()) {
        int x=q.top().second;
        if (-q.top().first!=dist[x]) {
            q.pop();
            continue;
        }
        q.pop();
        for (auto i:v[x]) {
            if (dist[i.first]==-1 || dist[x]+i.second<dist[i.first]) {
                dist[i.first]=dist[x]+i.second;
                q.push({-dist[i.first],i.first});
            }
        }
    }
}
int main () {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n;
    for (int i=1;i<=n;i++) cin >> l[i] >> r[i];
    build(1,1,n);
    for (int i=1;i<=n;i++) {
        c[i]=-1;
        find_passports(1,1,n,l[i],r[i],4*n+i);
    }
    dejkstra(4*n+1);
    dist[4*n+1]=1;
    for (int i=1;i<=n;i++) {
        if (dist[4*n+i]==-1) continue;
        c[i]=dist[4*n+i];
    }
    dejkstra(5*n);
    dist[5*n]=1;
    for (int i=1;i<=n;i++) {
        if (dist[4*n+i]==-1 || c[i]==-1) {
            c[i]=-1;
            continue;
        }
        c[i]+=dist[4*n+i];
    }
    for (int i=1;i<=n;i++) {
        if (c[i]==-1) continue;
        v[5*n+1].push_back({4*n+i,c[i]});
    }
    dejkstra(5*n+1);
    int q, t;
    cin >> q;
    for (int i=0;i<q;i++) {
        cin >> t;
        cout << max(-1,dist[4*n+t]-1) << endl;
    }
    return 0;
}

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