제출 #1221076

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1221076		madamadam3	Commuter Pass (JOI18_commuter_pass)	C++20	15 / 100	426 ms	23856 KiB

commuter_pass

#include <bits/stdc++.h>

using namespace std;

#define int long long int

using pi = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vpi = vector<pi>;
using vvpi = vector<vpi>;

const int MAXN = 100'001, MAXM = 200'001;
const int INF = numeric_limits<int>::max();
int n, m, X[MAXM], Y[MAXM], C[MAXM];
int S, T, U, V;
vi adj[MAXN];

void dijkstra(int u, vi &dist, vi &par) {
    dist.assign(n+1, INF);
    par.assign(n+1, -1);

    dist[u] = 0; par[u] = 0;
    priority_queue<pi, vector<pi>, greater<pi>> q;
    q.push({0, u});

    while (!q.empty()) {
        auto cur = q.top();
        q.pop();

        int cu = cur.second, cdist = cur.first;

        for (auto &el : adj[cu]) {
            int cv = X[el] == cu ? Y[el] : X[el];
            int vdist = C[el];

            if(dist[cu] + vdist < dist[cv]) {
                par[cv] = cu;
                dist[cv] = dist[cu] + vdist;
                q.push({dist[cu] + vdist, cv});
            }
        }
    }
}

signed main() {
    cin >> n >> m;
    cin >> S >> T >> U >> V;

    for (int i = 1; i <= m; i++) {
        cin >> X[i] >> Y[i] >> C[i];
        adj[X[i]].push_back(i);
        adj[Y[i]].push_back(i);
    }

    vi sd, spar;
    dijkstra(S, sd, spar);
    set<pi> clear_edges;
    int cur = T;
    while (spar[cur] != -1) {
        clear_edges.insert({min(cur, spar[cur]), max(cur,spar[cur])});
        cur = spar[cur];
    }

    for (int i = 1; i <= m; i++) {
        if (!clear_edges.count({min(X[i], Y[i]), max(X[i], Y[i])})) continue;
        C[i] = 0;
    }
    
    vi ud, upar;
    dijkstra(U, ud, upar);

    cout << ud[V];
    return 0;
}

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