Submission #1109784

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109784		_callmelucian	Passport (JOI23_passport)	C++14	100 / 100	603 ms	92704 KiB

passport

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 2e5 + 5, NODE = 9e5 + 5;
int dist[3][mn], distanc[NODE], leaf[NODE], node[NODE], n, maxNode;
vector<pii> adj[NODE];
bool vis[NODE];

void buildTree (int k, int l, int r) {
    maxNode = max(maxNode, k);
    if (l == r)
        return leaf[l] = k, void();
    int mid = (l + r) >> 1;
    adj[2 * k].emplace_back(k, 0), buildTree(2 * k, l, mid);
    adj[2 * k + 1].emplace_back(k, 0), buildTree(2 * k + 1, mid + 1, r);
}

void buildEdge (int idx, int a, int b, int k, int l, int r) {
    if (b < l || r < a) return;
    if (a <= l && r <= b)
        return adj[k].emplace_back(node[idx], 1), void();
    int mid = (l + r) >> 1;
    buildEdge(idx, a, b, 2 * k, l, mid);
    buildEdge(idx, a, b, 2 * k + 1, mid + 1, r);
}

void bfs (int save, int source) {
    for (int i = 1; i <= maxNode; i++)
        distanc[i] = INT_MAX, vis[i] = 0;
    distanc[leaf[source]] = 0;
    deque<int> dq; dq.push_back(leaf[source]);

    while (dq.size()) {
        int u = dq.front(); dq.pop_front();
        if (vis[u]) continue;
        vis[u] = 1;

        for (pii item : adj[u]) {
            int v, w; tie(v, w) = item;
            if (distanc[u] + w < distanc[v]) {
                distanc[v] = distanc[u] + w;
                if (w) dq.push_back(v);
                else dq.push_front(v);
            }
        }
    }

    for (int i = 1; i <= n; i++)
        dist[save][i] = distanc[node[i]];
}

void dijkstra (int save, vector<pii> &sources) {
    for (int i = 1; i <= maxNode; i++) distanc[i] = INT_MAX, vis[i] = 0;
    priority_queue<pii> pq;

    for (pii item : sources) {
        int u, dst; tie(u, dst) = item;
        pq.emplace(-dst, node[u]);
        distanc[node[u]] = dst;
    }

    while (pq.size()) {
        int u = pq.top().second; pq.pop();
        if (vis[u]) continue;
        vis[u] = 1;

        for (pii item : adj[u]) {
            int v, w; tie(v, w) = item;
            if (distanc[u] + w < distanc[v]) {
                distanc[v] = distanc[u] + w;
                pq.emplace(-distanc[v], v);
            }
        }
    }

    for (int i = 1; i <= n; i++)
        dist[save][i] = distanc[node[i]];
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> n;

    // build segment tree graph
    buildTree(1, 1, n);
    for (int i = 1; i <= n; i++) {
        node[i] = maxNode + i;
        adj[node[i]].emplace_back(leaf[i], 0);
    }
    maxNode += n;
    for (int i = 1; i <= n; i++) {
        int L, R; cin >> L >> R;
        buildEdge(i, L, R, 1, 1, n);
    }

    // phase 1: bfs from 1 and n
    bfs(0, 1), bfs(1, n);

    // phase 2: merge paths and continue with dijkstra
    vector<pii> sources;
    for (int i = 1; i <= n; i++)
        if (max(dist[0][i], dist[1][i]) != INT_MAX)
            sources.emplace_back(i, dist[0][i] + dist[1][i] - 1);
    dijkstra(2, sources);

    // answer queries
    int q; cin >> q;
    while (q--) {
        int x; cin >> x;
        cout << (dist[2][x] == INT_MAX ? -1 : dist[2][x]) << "\n";
    }

    return 0;
}

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