Submission #708507

#	Time	Username	Problem	Language	Result	Execution time	Memory
708507		finn__	Robot (JOI21_ho_t4)	C++17	100 / 100	618 ms	65956 KiB

Main

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

constexpr size_t N = 100000;

vector<tuple<size_t, size_t, size_t>> g[N];
map<size_t, size_t> ccost[N], f[N];
size_t d[N];

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

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

    for (size_t i = 0; i < m; i++)
    {
        size_t u, v, c, p;
        cin >> u >> v >> c >> p;
        g[u - 1].emplace_back(v - 1, c, p);
        g[v - 1].emplace_back(u - 1, c, p);
        ccost[u - 1][c] += p;
        ccost[v - 1][c] += p;
    }

    auto compare_second = [](tuple<size_t, size_t, size_t> const &a,
                             tuple<size_t, size_t, size_t> const &b)
    { return get<1>(a) > get<1>(b); };

    for (size_t i = 0; i < n; i++)
        sort(g[i].begin(), g[i].end(), compare_second);

    priority_queue<tuple<size_t, size_t, size_t>,
                   vector<tuple<size_t, size_t, size_t>>, decltype(compare_second)>
        q(compare_second);

    fill(d + 1, d + n, SIZE_MAX);
    q.emplace(0, 0, 0);

    while (!q.empty())
    {
        auto const [u, dis, c] = q.top();
        q.pop();

        if ((!c && dis != d[u]) || (c && dis != f[u][c]))
            continue;

        if (c)
        {
            auto it = lower_bound(
                g[u].begin(), g[u].end(), (tuple<size_t, size_t, size_t>){0, c, 0},
                compare_second);
            while (it != g[u].end() && get<1>(*it) == c)
            {
                if (dis + ccost[u][c] - get<2>(*it) < d[get<0>(*it)])
                {
                    d[get<0>(*it)] = dis + ccost[u][c] - get<2>(*it);
                    q.emplace(get<0>(*it), d[get<0>(*it)], 0);
                }
                it++;
            }
            continue;
        }
        for (auto const &[v, ec, p] : g[u])
        {
            if (f[v].find(ec) == f[v].end() || dis < f[v][ec])
            {
                f[v][ec] = dis;
                q.emplace(v, dis, ec);
            }
            if (dis + p < d[v])
            {
                d[v] = dis + p;
                q.emplace(v, d[v], 0);
            }
            if (dis + ccost[u][ec] - p < d[v])
            {
                d[v] = dis + ccost[u][ec] - p;
                q.emplace(v, d[v], 0);
            }
        }
    }

    cout << (d[n - 1] == SIZE_MAX ? -1 : (int64_t)d[n - 1]) << '\n';
}

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42