#include <bits/stdc++.h> using namespace std; #define FOR(i, a, b) for(int i = a; i <= b; i++) #define FOD(i, a, b) for(int i = a; i >= b; i--) #define fi first #define se second #define ll long long #define db double #define ii pair<int,int> #define pb push_back #define MASK(i) (1LL << i) #define sq(i) (1LL * (i) * (i)) #define task "task" const ll INF = 1e18; const int inf = 1e9; const int N = 2e5 + 4; int n, k; vector<ii> g[N]; ll d[N], r[N]; bool ch[N]; void dfs(int u, int p, ll x) { r[u] = 0; d[u] = -1; ll maxr = 0, maxd = -1; for(ii H : g[u]) { int v = H.fi; int w = H.se; if(v == p) continue; dfs(v, u, x); if(r[v] != -1) { if(r[v] + w > x) { maxd = max(maxd, x - w); ch[v] = 1; } else { maxr = max(maxr, r[v] + w); } } else maxd = max(maxd, d[v] - w); } if(maxr <= maxd) { if(maxd != -1) { d[u] = maxd; r[u] = -1; } } else { r[u] = maxr; } } bool check(ll x) { FOR(i, 1, n) ch[i] = 0; dfs(1, -1, x); if(r[1] != -1) ch[1] = 1; int cnt = 0; FOR(i, 1, n) cnt += ch[i]; return cnt <= k; } void solve() { ll l = 0, r = 2e14, res = 0; while(l <= r) { ll mid = l + r >> 1; if(check(mid)) { res = mid; r = mid - 1; } else l = mid + 1; } cout << res << '\n'; check(res); int cnt = 0; FOR(i, 1, n) cnt += ch[i]; FOR(i, 1, n) { if(ch[i]) cout << i << ' '; else if(cnt < k) { cout << i << ' '; cnt++; } } } signed main() { if(fopen(task".inp", "r")) { freopen(task".inp", "r", stdin); //freopen(task".out", "w", stdout); } ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int tc = 1; // cin >> tc; while(tc--) { cin >> n >> k; FOR(i, 1, n - 1) { int u, v, w; cin >> u >> v >> w; g[u].pb({v, w}); g[v].pb({u, w}); } solve(); } }

Main.cpp: In function 'int main()':
Main.cpp:92:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~