#include //typedef //-------------------------#include const double pi = 3.141592653589793238462643383279; using namespace std; //conversion //------------------------------------------ inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v; } template inline string toString(T x) { ostringstream sout; sout << x; return sout.str(); } inline int readInt() { int x; scanf("%d", &x); return x; } //typedef //------------------------------------------ typedef vector VI; typedef vector VVI; typedef vector VS; typedef pair PII; typedef pair PLL; typedef pair TIII; typedef long long LL; typedef unsigned long long ULL; typedef vector VLL; typedef vector VVLL; //container util //------------------------------------------ #define ALL(a) (a).begin(),(a).end() #define RALL(a) (a).rbegin(), (a).rend() #define PB push_back #define MP make_pair #define SZ(a) int((a).size()) #define SQ(a) ((a)*(a)) #define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i) #define EXIST(s,e) ((s).find(e)!=(s).end()) #define SORT(c) sort((c).begin(),(c).end()) //repetition //------------------------------------------ #define FOR(i,s,n) for(int i=s;i<(int)n;++i) #define REP(i,n) FOR(i,0,n) #define MOD 1000000007 #define rep(i, a, b) for(int i = a; i < (b); ++i) #define trav(a, x) for(auto& a : x) #define all(x) x.begin(), x.end() #define sz(x) (int)(x).size() typedef long long ll; typedef pair pii; typedef vector vi; const double EPS = 1E-8; #define chmin(x,y) x=min(x,y) #define chmax(x,y) x=max(x,y) class UnionFind { public: vector par; vector siz; UnionFind(int sz_): par(sz_), siz(sz_, 1) { for (ll i = 0; i < sz_; ++i) par[i] = i; } void init(int sz_) { par.resize(sz_); siz.assign(sz_, 1LL); for (ll i = 0; i < sz_; ++i) par[i] = i; } int root(int x) { while (par[x] != x) { x = par[x] = par[par[x]]; } return x; } bool merge(int x, int y) { x = root(x); y = root(y); if (x == y) return false; if (siz[x] < siz[y]) swap(x, y); siz[x] += siz[y]; par[y] = x; return true; } bool issame(int x, int y) { return root(x) == root(y); } int size(int x) { return siz[root(x)]; } }; ll modPow(ll x, ll n, ll mod = MOD){ if(n <= 0) return 1; ll res = 1; while(n){ if(n&1) res = (res * x)%mod; res %= mod; x = x * x %mod; n >>= 1; } return res; } #define SIEVE_SIZE 5000000+10 bool sieve[SIEVE_SIZE]; void makeSieve(){ for(int i=0; i tmp{x1,x2,x3}; sort(all(tmp)); if(tmp[0] != tmp[1] && tmp[1] != tmp[2] && tmp[0] != tmp[2]){ if(tmp[1] == x1 || tmp[1] == x3){ return true; } } return false; } vector ans; vector>> g(210); int N, M, S, G; void dfs(int V, int par, int t, vector v){ if(V == S){ reverse(all(v)); if(ans.size() == 0){ ans = v; }else{ bool ok = false; for(int i=0; i v[i]){ ans = v; return; }else if(ans[i] < v[i]){ return; } } if(ans.size() > v.size()){ ans = v; } } return; } for(int i=0; i t) continue; v.push_back(g[V][i].first); dfs(g[V][i].first, V, t-g[V][i].second, v); v.pop_back(); } } int main() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cin >> N >> M >> S>> G; vector> dp(N+10, vector(N+10,10000000)); REP(i,M){ int a, b, c; cin >> a >> b >> c; g[a].push_back({b, c}); g[b].push_back({a, c}); dp[a][b] = c; dp[b][a] = c; } REP(k,N){ REP(i,N){ REP(j,N){ dp[i][j] = min(dp[i][j], dp[i][k] + dp[k][j]); } } } int t = dp[S][G]; vector v; v.push_back(G); dfs(G, -1, t, v); for(int i=0; i