BOJ 21940 가운데에서 만나기

void solve(){
    cin >> N >> M;

    rep(i, 0, N) rep(j, 0, N) cost[i][j] = 1e15;
    rep(i, 0, N) cost[i][i] = 0;
    rep(i, 0, M){
        int u, v, w; cin >> u >> v >> w;
        u--; v--;
        cost[u][v] = w;
    }
    rep(k, 0, N) rep(i, 0, N) rep(j, 0, N) cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);

    cin >> K;
    vector<int> v(K), ans;
    rep(i, 0, K) cin >> v[i];

    ll mn = 1e15;
    rep(X, 0, N){
        ll tmp = 0;
        for(auto c: v) tmp = max(tmp, cost[X][c-1] + cost[c-1][X]);
        if(tmp < mn){
            mn = tmp;
            ans.clear();
        }
        if(tmp == mn) ans.push_back(X+1);
    }
    for(auto c: ans) cout << c << ' ';
}