Submission #891236

#	Time	Username	Problem	Language	Result	Execution time	Memory
891236		Mr_Ell	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	123 ms	16464 KiB

commuter_pass

#ifdef LOCAL
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const ll INF = LLONG_MAX, MOD = 1e9 + 7, P = 239;
const ld PI = 3.1415926535897938462643383279502, EPS = 1e-7;

template <typename T>
inline ll sz(const T &a) {
    return a.size();
}

template <typename T, typename C>
istream &operator >> (istream &in, pair<T, C> &a) {
    return in >> a.first >> a.second;
}

template <typename T, typename C>
ostream &operator << (ostream &out, pair<T, C> a) {
    return out << a.first << ' ' << a.second;
}

template <typename T>
istream & operator >> (istream &in, vector<T> &a) {
    for (auto &i : a) {
        in >> i;
    }
    return in;
}

template <typename T>
ostream &operator << (ostream &out, vector<T> a) {
    for (auto i : a) {
        out << i << ' ';
    }
    return out;
}

template <typename T>
void prnt(vector<T> a, string c = "\n") {
    for (T i : a) {
        cout << i << c;
    }
}

const ll MAXN = 1e5 + 1;
vector<pair<ll, ll>> g[MAXN];
ll dp[MAXN][2];

void dijkstra(vector<ll> &d, int start) {
    fill(d.begin(), d.end(), INF);
    set<pair<ll, ll>> q;
    q.insert({0, start});
    d[start] = 0;
    while (!q.empty()) {
        auto [dist, v] = *q.begin();
        q.erase(q.begin());
        if (dist > d[v]) {
            continue;
        }
        for (auto [u, w] : g[v]) {
            if (d[u] > d[v] + w) {
                d[u] = d[v] + w;
                q.insert({d[u], u});
            }
        }
    }
}

void solve() {
    int n, m, s, t, u, v;
    cin >> n >> m >> s >> t >> u >> v;
    for (int i = 0; i < n; ++i) {
        int a, b, w;
        cin >> a >> b >> w;
        g[a].push_back({b, w});
        g[b].push_back({a, w});
    }
    vector<ll> du(n + 1), dv(n + 1), ds(n + 1), dt(n + 1);
    dijkstra(du, u);
    dijkstra(dv, v);
    dijkstra(ds, s);
    dijkstra(dt, t);

    vector<ll> flex(n);
    iota(flex.begin(), flex.end(), 1ll);
    sort(flex.begin(), flex.end(), [&](int a, int b) {
        return ds[a] < ds[b];
    });
    fill(dp[0], dp[0] + MAXN * 2, INF);
    dp[s][0] = ds[u];
    dp[s][1] = ds[v];
    for (int i = 0; i < n; ++i) {
        int a = flex[i];
        if (dp[a][0] == INF) {
            continue;
        }
        for (auto [b, w] : g[a]) {
            if (dt[b] + w + ds[a] == ds[t]) {
                dp[b][0] = min(dp[a][0], du[b]);
                dp[b][1] = min(dp[a][1], dv[b]);
            }
        }
    }
    ll ans = dv[u];
    for (int i = 1; i <= n; ++i) {
        if (dp[i][0] == INF) {
            continue;
        }
        ans = min(ans, min(dp[i][0] + dv[i], dp[i][1] + du[i]));
    }
    cout << ans;
}

signed main() {
#ifdef LOCAL
    freopen("inp.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    freopen("err.txt", "w", stderr);

    auto start_time = clock();
#endif
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int times = 1;
//    cin >> times;
    while (times--)
        solve(), cout << '\n';

#ifdef LOCAL
    auto end_time = clock();
    cerr << setprecision(3) << fixed << "Execution time: " << (end_time - start_time) * (int) 1e3 / CLOCKS_PER_SEC << " ms\n";
#endif
    return 0;
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45