Submission #369300

#	Time	Username	Problem	Language	Result	Execution time	Memory
369300		Lam_lai_cuoc_doi	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	347 ms	23020 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;

const bool typetest = 0;
const int N = 1e5 + 5;
const ll Inf = 1e17;
int n, m, s, t, u, v, id[N];
vector<pair<int, ll>> adj[N];
ll d[4][N], dp[N][3];

void Read()
{
    cin >> n >> m >> s >> t >> u >> v;
    for (int i = 1; i <= m; ++i)
    {
        int x, y, w;
        cin >> x >> y >> w;
        adj[x].push_back({y, w});
        adj[y].push_back({x, w});
    }
}

void Dijkstra(int x, ll d[N])
{
    fill_n(d, N, Inf);
    d[x] = 0;
    struct Tque
    {
        int v;
        ll w;
        Tque(const int &v, const ll &w) : v(v), w(w)
        {
        }
        bool operator<(const Tque &a) const
        {
            return w > a.w;
        }
    };
    priority_queue<Tque> s;
    s.push({x, 0});
    while (s.size())
    {
        Tque c = s.top();
        s.pop();
        if (d[c.v] != c.w)
            continue;
        for (auto i : adj[c.v])
            if (d[i.first] > c.w + i.second)
            {
                d[i.first] = c.w + i.second;
                s.push({i.first, d[i.first]});
            }
    }
}

void Solve()
{
    Dijkstra(s, d[1]);
    Dijkstra(u, d[2]);
    Dijkstra(v, d[3]);
    for (int i = 1; i <= n; ++i)
        id[i] = i;
    sort(id + 1, id + n + 1, [&](const int &x, const int &y) {
        return d[1][x] < d[1][y];
    });
    fill_n(&dp[0][0], N * 3, Inf);
    for (int i = 1; i <= n; ++i)
    {
        dp[id[i]][0] = d[2][id[i]];
        dp[id[i]][1] = d[3][id[i]];
        for (auto j : adj[id[i]])
            if (d[1][j.first] + j.second == d[1][id[i]])
            {
                dp[id[i]][0] = min(dp[j.first][0], dp[id[i]][0]);
                dp[id[i]][1] = min(dp[j.first][1], dp[id[i]][1]);
                dp[id[i]][2] = min(dp[j.first][2], dp[id[i]][2]);
            }
        dp[id[i]][2] = min(dp[id[i]][2], min(dp[id[i]][0] + d[3][id[i]], dp[id[i]][1] + d[2][id[i]]));
    }
    cout << min(dp[t][2], d[2][v]);
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t(1);
    if (typetest)
        cin >> t;
    for (int _ = 1; _ <= t; ++_)
    {
        Read();
        Solve();
    }
}

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 45 / 45