Submission #88269

#	Time	Username	Problem	Language	Result	Execution time	Memory
88269		tieunhi	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	585 ms	76516 KiB

commuter_pass

#include <bits/stdc++.h>
#define pii pair<int, int>
#define mp make_pair
#define F first
#define S second
#define PB push_back
#define FOR(i, u, v) for (int i = u; i <= v; i++)
#define FORD(i, v, u) for (int i = v; i >= u; i--)
#define N 100005
#define maxc 1ll*100000000000000007
#define ll long long

using namespace std;

int n, m, S, T, U, V, in[N];
ll ans[N], ans2[N], d[5][N];
vector<int> g[N];
vector<pii> a[N];
void setup()
{
    cin >> n >> m >> S >> T >> U >> V;
    FOR(i, 1, m)
    {
        int u, v, w; cin >> u >> v >> w;
        a[u].PB(mp(v, w));
        a[v].PB(mp(u, w));
    }
}
void IJK(int s, ll dis[])
{
    FOR(i, 1, n) dis[i] = maxc;
    dis[s] = 0;
    priority_queue<pair<ll, int> > q;
    q.push(mp(0, s));
    while (!q.empty())
    {
        int u = q.top().S;
        ll l = -q.top().F;
        q.pop();
        if (dis[u] < l) continue;
        for (auto z : a[u])
        {
            int v = z.F;
            int w = z.S;
            if (dis[v] > l + w)
            {
                dis[v] = l + w;
                q.push(mp(-dis[v], v));
            }
        }
    }
}
void add_edge(int u, int v)
{
    g[v].PB(u);
    in[u]++;
}
void solve()
{
    IJK(S, d[1]);
    IJK(T, d[2]);
    FOR(u, 1, n)
        for (auto z : a[u])
        {
            int v = z.F;
            int w = z.S;
            if (d[1][u] + d[2][v] + w == d[1][T])
                add_edge(u, v);
        }
    IJK(U, d[3]);
    IJK(V, d[4]);
    FOR(i, 1, n) ans[i] = d[4][i], ans2[i] = d[3][i];
    queue<int> q;
    q.push(T);
    ll res = d[3][V];
    while (!q.empty())
    {
        int u = q.front(); q.pop();
        ll l = ans[u];
        ll l2 = ans2[u];
        res = min(res, l + d[3][u]);
        res = min(res, l2 + d[4][u]);
        for (auto v : g[u])
        {
            ans[v] = min(ans[v], ans[u]);
            ans2[v] = min(ans2[v], ans2[u]);
            in[v]--;
            if (in[v] == 0) q.push(v);
        }
    }
    cout <<res;
}
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    //freopen("INP.TXT", "r", stdin);
    setup();
    solve();
}

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