Submission #298769

#	Time	Username	Problem	Language	Result	Execution time	Memory
298769		HynDuf	Commuter Pass (JOI18_commuter_pass)	C++11	100 / 100	410 ms	23164 KiB

commuter_pass

#include <bits/stdc++.h>

#define task "C"
#define all(v) (v).begin(), (v).end()
#define rep(i, l, r) for (int i = (l); i <= (r); ++i)
#define Rep(i, r, l) for (int i = (r); i >= (l); --i)
#define DB(X) { cerr << #X << " = " << (X) << '\n'; }
#define DB1(A, _) { cerr << #A << "[" << _ << "] = " << (A[_]) << '\n'; }
#define DB2(A, _, __) { cerr << #A << "[" << _ << "][" << __ << "] = " << (A[_][__]) << '\n'; }
#define DB3(A, _, __, ___) { cerr << #A << "[" << _ << "][" << __ << "][" << ___ << "] = " << (A[_][__][___]) << '\n'; }
#define PR(A, l, r) { cerr << '\n'; rep(_, l, r) DB1(A, _); cerr << '\n';}
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back
#define pf push_front
#define F first
#define S second
#define by(x) [](const auto& a, const auto& b) { return a.x < b.x; } // sort(arr, arr + N, by(a));
#define next ___next
#define prev ___prev
#define y1 ___y1
#define left ___left
#define right ___right
#define y0 ___y0
#define div ___div
#define j0 ___j0
#define jn ___jn

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using namespace std;
typedef pair<ll, int> ii;
typedef pair<ii, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vl;
const int N = 1e5 + 2;
const ll INF = 1e18;
int n, m, S, T, U, V;
ll dp[N], ans;
vii g[N];
vl dS, dT, dU, dV;
void dij(int r, vl &d)
{
    d.assign(n + 1, INF);
    d[r] = 0;
    priority_queue<ii, vii, greater<ii> > pq;
    pq.push({0, r});
    while (!pq.empty())
    {
        int u = pq.top().S;
        ll du = pq.top().F;
        pq.pop();
        if (du != d[u]) continue;
        for (ii v : g[u]) if (d[v.F] > du + v.S)
        {
            d[v.F] = du + v.S;
            pq.push({d[v.F], v.F});
        }
    }
}
bool in[N];
void updDP1(int u)
{
    in[u] = 1;
    dp[u] = dV[u];
    for (ii v : g[u]) if (dS[u] + v.S + dT[v.F] == dS[T])
    {
        if (!in[v.F]) updDP1(v.F);
        dp[u] = min(dp[u], dp[v.F]);
    }
    ans = min(ans, dU[u] + dp[u]);
}
void updDP(int u)
{
    in[u] = 1;
    dp[u] = dV[u];
    for (ii v : g[u]) if (dT[u] + v.S + dS[v.F] == dS[T])
    {
        if (!in[v.F]) updDP(v.F);
        dp[u] = min(dp[u], dp[v.F]);
    }
    ans = min(ans, dU[u] + dp[u]);
}
int main()
{
#ifdef HynDuf
    freopen(task".in", "r", stdin);
    //freopen(task".out", "w", stdout);
#else
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
#endif
    cin >> n >> m >> S >> T >> U >> V;
    rep(i, 1, m)
    {
        int u, v, w;
        cin >> u >> v >> w;
        g[u].eb(v, w);
        g[v].eb(u, w);
    }
    dij(S, dS);
    dij(T, dT);
    dij(U, dU);
    dij(V, dV);
    ans = dU[V];
    fill(dp + 1, dp + 1 + n, INF);
    updDP(T);
    fill(dp + 1, dp + 1 + n, INF);
    fill(in + 1, in + 1 + n, 0);
    updDP1(S);
    cout << ans;
    return 0;
}

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