Submission #889545

#	Time	Username	Problem	Language	Result	Execution time	Memory
889545		_callmelucian	Tourism (JOI23_tourism)	C++14	17 / 100	77 ms	24796 KiB

tourism

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

typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;
#define all(a) a.begin(), a.end()

const int mn = 1e5 + 10;
int up[mn][17], sight[mn];
vector<int> adj[mn];
pii qry[mn];
int n, m, q;
bool stickTree = 1;

/* subtask */
namespace sub_2 {

int sz[mn], mark[mn];

int szDfs (int u, int p) {
    sz[u] = mark[u];
    for (int v : adj[u])
        if (v != p) sz[u] += szDfs(v, u);
    return sz[u];
}

int dfs (int u, int p, bool toParent = 0) {
    int child = 0, ans = 0;
    for (int v : adj[u])
        if (v != p && sz[v]) child++;
    toParent |= (child > 1 || mark[u]);

    for (int v : adj[u]) {
        if (v == p || !sz[v]) continue;
        ans += dfs(v, u, toParent);
    }
    return ans + toParent;
}

void solve() {
    for (int j = 0; j < q; j++) {
        for (int i = 1; i <= n; i++) mark[i] = 0;
        for (int i = qry[j].first; i <= qry[j].second; i++) mark[sight[i]] = 1;
        szDfs(1, 1);
        cout << dfs(1, 1) << "\n";
    }
}

bool check() {
    return n <= 2000 && m <= 2000 && q <= 2000;
}

}
/* end of subtask */

/* subtask */
namespace sub_3 {

int max_spt[mn][17], min_spt[mn][17];

int query (int l, int r) {
    int p = 31 - __builtin_clz(r - l + 1);
    int lo = min(min_spt[l][p], min_spt[r - (1 << p) + 1][p]);
    int hi = max(max_spt[l][p], max_spt[r - (1 << p) + 1][p]);
    return hi - lo + 1;
}

void solve() {
    for (int i = 1; i <= m; i++) max_spt[i][0] = min_spt[i][0] = sight[i];
    for (int s = 1; (1 << s) <= m; s++) {
        for (int i = 1; i + (1 << s) - 1 <= m; i++) {
            int p = s - 1;
            max_spt[i][s] = max(max_spt[i][p], max_spt[i + (1 << p)][p]);
            min_spt[i][s] = min(min_spt[i][p], min_spt[i + (1 << p)][p]);
        }
    }
    for (int i = 0; i < q; i++) {
        int l, r; tie(l, r) = qry[i];
        cout << query(l, r) << "\n";
    }
}

bool check() {
    return stickTree;
}

}
/* end of subtask */

/* subtask */
namespace sub_4 {

int spt[mn][21], up[mn][21], depth[mn], num[mn], sz[mn];
int timeDfs;

int dfs (int u, int p, int d) {
    up[u][0] = p, depth[u] = d, num[u] = ++timeDfs, sz[u] = 1;
    for (int i = 1; i < 21; i++) up[u][i] = up[up[u][i - 1]][i - 1];
    for (int v : adj[u])
        if (v != p) sz[u] += dfs(v, u, d + 1);
    return sz[u];
}

int goUp (int a, int k) {
    int LOG = 31 - __builtin_clz(k);
    for (int i = 0; i <= LOG; i++)
        if (k & (1 << i)) a = up[a][i];
    return a;
}

int lca (int a, int b) {
    a = goUp(a, max(0, depth[a] - depth[b]));
    b = goUp(b, max(0, depth[b] - depth[a]));
    if (a == b) return a;

    for (int i = 20; i >= 0; i--)
        if (up[a][i] != up[b][i]) a = up[a][i], b = up[b][i];
    return up[a][0];
}

int dist (int a, int b) {
    return depth[a] + depth[b] - 2 * depth[lca(a, b)];
}

struct BIT {
    vector<int> tr;
    BIT (int sz) : tr(4 * sz) {}

    int p (int k) { return k & -k; }

    void update (int k, int val) {
        for (; k < tr.size(); k += p(k)) tr[k] += val;
    }

    int sum (int k, int ans = 0) {
        for (; k; k -= p(k)) ans += tr[k];
        return ans;
    }

    int query (int l, int r) { return sum(r) - sum(l - 1); }
};

bool inTree (int subtr, int node) {
    return num[subtr] <= num[node] && num[node] < num[subtr] + sz[subtr];
}

int query (int l, int r) {
    int p = 31 - __builtin_clz(r - l + 1);
    return lca(spt[l][p], spt[r - (1 << p) + 1][p]);
}

void solve() {
    dfs(1, 1, 1);
    for (int i = 1; i <= m; i++) spt[i][0] = sight[i];
    for (int s = 1; (1 << s) <= m; s++) {
        for (int i = 1; i + (1 << s) - 1 <= m; i++) {
            int p = s - 1;
            spt[i][s] = lca(spt[i][p], spt[i + (1 << p)][p]);
        }
    }

    BIT tree(n);
    for (int i = 0; i < q; i++) {
        int ans = 0, l = qry[i].first;
        for (int r = qry[i].first; r <= qry[i].second; r++) {
            if (l == r) ans = 1;
            else if (inTree(query(l, r - 1), sight[r])) {
                int node = sight[r];
                for (int i = 20; i >= 0; i--) {
                    int p = up[node][i];
                    if (!tree.query(num[p], num[p] + sz[p] - 1)) node = p;
                }
                ans += depth[sight[r]] - depth[node] + 1;
            }
            else ans += dist(query(l, r - 1), sight[r]);

            tree.update(num[sight[r]], 1);
        }
        cout << ans << "\n";
    }
}

bool check() {
    if (qry[0].first != 1 || qry[q - 1].second != m) return 0;
    for (int i = 0; i < q - 1; i++)
        if (qry[i].second + 1 != qry[i + 1].first) return 0;
    return 1;
}

}
/* end of subtask */

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

    cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        int a, b; cin >> a >> b;
        stickTree &= (a == i && b == i + 1);
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for (int i = 1; i <= m; i++) cin >> sight[i];
    for (int i = 0; i < q; i++) {
        int l, r; cin >> l >> r;
        qry[i] = {l, r};
    }

    if (sub_2::check()) return sub_2::solve(), 0;
    if (sub_3::check()) return sub_3::solve(), 0;
    if (sub_4::check()) return sub_4::solve(), 0;

    return 0;
}

Compilation message (stderr)

tourism.cpp: In member function 'void sub_4::BIT::update(int, int)':
tourism.cpp:134:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  134 |         for (; k < tr.size(); k += p(k)) tr[k] += val;
      |                ~~^~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 7 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 41