题解

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

const long long INF = 1e18;

vector<vector<pair<int, int>>> adj;

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

int n, m;
if (!(cin >> n >> m)) return 0;

adj.resize(n + 1);

for (int i = 0; i < m; i++) {
    int u, v, w;
    cin >> u >> v >> w;
    adj[u].push_back({v, w});
    adj[v].push_back({u, w});
}

vector<long long> dist(n + 1, INF);
vector<int> pre(n + 1, -1);

priority_queue<pair<long long, int>, vector<pair<long long, int>>, greater<pair<long long, int>>> pq;

dist[1] = 0;
pq.push({0, 1});

while (!pq.empty()) {
    auto [d, u] = pq.top();
    pq.pop();

    if (d > dist[u]) continue;

    for (auto [v, w] : adj[u]) {
        if (dist[u] + w < dist[v]) {
            dist[v] = dist[u] + w;
            pre[v] = u;
            pq.push({dist[v], v});
        }
    }
}

if (dist[n] == INF) {
    cout << -1 << endl;
} else {
    vector<int> path;
    int curr = n;
    while (curr != -1) {
        path.push_back(curr);
        curr = pre[curr];
    }
    
    reverse(path.begin(), path.end());

    for (int i = 0; i < path.size(); i++) {
        cout << path[i] << " ";
    }
    cout << endl;
}

return 0;

}