Submission #685337

#	Time	Username	Problem	Language	Result	Execution time	Memory
685337		saayan007	Commuter Pass (JOI18_commuter_pass)	C++17	16 / 100	210 ms	19856 KiB

commuter_pass

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

using ll = long long;
using pi = pair<int, int>;
using pl = pair<long long, long long>;
using vi = vector<int>;
using vl = vector<long long>;
using vpi = vector<pair<int, int>>;
using vpl = vector<pair<long long, long long>>;

#define fur(i, a, b) for(ll i = a; i <= (ll)b; ++i)
#define ruf(i, a, b) for(ll i = a; i >= (ll)b; --i)
#define fr first 
#define sc second
#define mp make_pair
#define pb emplace_back
#define nl "\n"
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()

const ll mxn = 1e5L + 1;
const ll inf = 1e16L;
ll n, m, s, t, u, v;
vpl adj[mxn];

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

    cin >> n >> m >> s >> t >> u >> v;
    fur(i, 1, m) {
        ll a, b, c;
        cin >> a >> b >> c;
        adj[a].pb(b, c);
        adj[b].pb(a, c);
    }

    priority_queue<pl> pq;
    ll dist[n + 1];
    fur(i, 1, n) {
        dist[i] = inf;
    }

    dist[s] = 0;
    pq.emplace(-dist[s], s);
    while(!pq.empty()) {
        ll a = pq.top().sc;
        if(dist[a] + pq.top().fr != 0) {
            pq.pop();
            continue;
        }
        pq.pop();

        for(auto [b, c] : adj[a]) {
            if(dist[b] > dist[a] + c) {
                dist[b] = dist[a] + c;
                pq.emplace(-dist[b], b);
            }
        }
    }

    bool zer[n + 1] = {};
    pq.emplace(dist[t], t);
    while(!pq.empty()) {
        ll a = pq.top().sc;
        pq.pop();
        if(zer[a])
            continue;
        zer[a] = 1;

        for(auto [b, c] : adj[a]) {
            if(dist[a] - c == dist[b]) {
                pq.emplace(dist[b], b);
            }
        }
    }

    ll ans = inf;
    fur(i, 1, n) 
        dist[i] = inf;
    dist[v] = 0;
    pq.emplace(-dist[v], v);
    while(!pq.empty()) {
        ll a = pq.top().sc;
        // cout << a << ' ' << dist[a] << nl;;
        if(dist[a] + pq.top().fr != 0) {
            pq.pop();
            continue;
        }
        pq.pop();
        if(zer[a]) {
            ans = min(ans, dist[a]);
        }

        for(auto [b, c] : adj[a]) {
            if(zer[a] && zer[b])
                c = 0;
            if(dist[b] > dist[a] + c) {
                dist[b] = dist[a] + c;
                pq.emplace(-dist[b], b);
            }
        }
    }
    // cout <<nl;
    // fur(i, 1, n) {
        // cout << dist[i] << ' ';
    // }
    // cout << nl;
    cout << ans << nl;
}

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