Dijkstra || MINPATH

#include <bits/stdc++.h>
#define int long long
#define Co_mot_su_that_la_ return
using namespace std;
const int Minh_dep_trai = 0;
const int N = 100005;
const int inf = 1000000;
typedef pair<int,int> ii;
typedef vector<ii> vii;

int n,m,s,t,nodel;
vii a[N];
int d[N],trace[N];
stack<int> st;

void truyvet()
{
    while (t != -1)
    {
        ++nodel;
        st.push(t);
        t = trace[t];
    }
    cout << nodel << endl;
    while (st.size())
    {
        int v = st.top();
        st.pop();
        cout << v << " ";
    }
}

void dijkstra(int s)
{
    for(int i=1; i<=n; ++i) d[i]=inf;
    d[s]=0;
    priority_queue<ii, vii, greater<ii>> qu;
    qu.push(ii(1,0));
    while (qu.size())
    {
        int u = qu.top().first;
        int du = qu.top().second;
        qu.pop();
        if (du != d[u]) continue;
        for(auto v : a[u])
        {
            if (d[v.first] > du + v.second)
            {
                d[v.first] = du + v.second;
                trace[v.first] = u;
                qu.push(ii(v.first,d[v.first]));
            }
        }
    }
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    freopen("MINPATH.INP","r",stdin);
    freopen("MINPATH.OUT","w",stdout);
    cin >> n >> m >> s >> t;
    for(int i=1; i<=m; ++i)
    {
        int u,v,z;
        cin >> u >> v >> z;
        a[u].push_back(ii(v,z));
        a[v].push_back(ii(u,z));
    }
    for(int i=1; i<=n; ++i) trace[i] = -1;
    dijkstra(s);
    cout << d[t] << endl;
    truyvet();
    Co_mot_su_that_la_ Minh_dep_trai;
}