Submission #796285

#	Time	Username	Problem	Language	Result	Execution time	Memory
796285		finn__	Tourism (JOI23_tourism)	C++17	28 / 100	5042 ms	23740 KiB

tourism

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

constexpr size_t N = 100000, LGN = 18;

size_t c[N], e[N], anc[LGN][N], h[N], preorder[N];
vector<size_t> g[N];

size_t traverse(size_t u, size_t p, size_t i = 0)
{
    preorder[u] = i++;
    for (auto const &v : g[u])
        if (v != p)
        {
            h[v] = h[u] + 1;
            anc[0][v] = u;
            for (size_t i = 1; i < LGN; ++i)
                anc[i][v] = anc[i - 1][anc[i - 1][v]];
            i = traverse(v, u, i);
        }
    return i;
}

size_t lift(size_t u, size_t d)
{
    size_t z = 0;
    while (d)
    {
        if (d & 1)
            u = anc[z][u];
        ++z;
        d >>= 1;
    }
    return u;
}

size_t lca(size_t u, size_t v)
{
    if (h[u] < h[v])
        swap(u, v);
    u = lift(u, h[u] - h[v]);
    if (u == v)
        return u;
    for (size_t i = LGN - 1; i < LGN; --i)
        if (anc[i][u] != anc[i][v])
            u = anc[i][u], v = anc[i][v];
    return anc[0][u];
}

size_t distance(size_t u, size_t v)
{
    return h[u] + h[v] - (h[lca(u, v)] << 1);
}

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

    size_t n, m, q;
    cin >> n >> m >> q;

    for (size_t i = 0; i < n - 1; ++i)
    {
        size_t u, v;
        cin >> u >> v;
        g[u - 1].push_back(v - 1);
        g[v - 1].push_back(u - 1);
    }

    traverse(0, -1);

    for (size_t i = 0; i < m; ++i)
        cin >> c[i], --c[i];

    while (q--)
    {
        size_t l, r;
        cin >> l >> r, --l, --r;
        memcpy(e + l, c + l, (r - l + 1) * sizeof *c);
        sort(e + l, e + r + 1, [](size_t u, size_t v)
             { return preorder[u] < preorder[v]; });
        size_t distance_sum = distance(e[l], e[r]);
        for (size_t i = l; i < r; ++i)
            distance_sum += distance(e[i], e[i + 1]);
        cout << (distance_sum >> 1) + 1 << '\n';
    }
}

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