#include #define ll long long #define INF 1000000005 #define MOD 1000000007 #define EPS 1e-10 #define rep(i,n) for(int i=0;i<(int)n;++i) #define each(a, b) for(auto (a): (b)) #define all(v) (v).begin(),(v).end() #define fi first #define se second #define pb push_back #define show(x) cout <<#x<<" = "<<(x)<P; const int MAX_N = 201; struct edge{ int to; int cost; }; int d[MAX_N]; vector G[MAX_N]; int pre[MAX_N]; void dijkstra(int s) { priority_queue,greater

> que; d[s] = 0; que.push(P(0,s)); while(!que.empty()){ P p = que.top(); que.pop(); int v = p.second; if(d[v] < p.first) continue; vector::iterator it = G[v].begin(); rep(i,G[v].size()){ if(d[G[v][i].to] > d[v] + G[v][i].cost){ pre[G[v][i].to] = v; d[G[v][i].to] = d[v] + G[v][i].cost; que.push(P(d[G[v][i].to],G[v][i].to)); }else if(d[G[v][i].to] == d[v] + G[v][i].cost){ pre[G[v][i].to] = min(pre[G[v][i].to],v); } } } } int main() { int n,m,s,g; cin >> n >> m >> s >> g; rep(i,m){ int a,b,c; cin >> a >> b >> c; G[a].pb({b,c}); G[b].pb({a,c}); } rep(i,n){ pre[i] = d[i] = INF; } dijkstra(s); vector route; int nw = g; route.pb(g); while(nw != s){ nw = pre[nw]; route.pb(nw); } reverse(all(route)); int num = (int)route.size(); rep(i,num-1){ cout << route[i] << " "; } cout << route[num-1] << endl; return 0; }