이 제출은 이전 버전의 oj.uz에서 채점하였습니다. 현재는 제출 당시와는 다른 서버에서 채점을 하기 때문에, 다시 제출하면 결과가 달라질 수도 있습니다.
#include <bits/stdc++.h>
#define Y8o "KTREE"
#define maxn (int) 2e5 + 5
#define ll long long
#define pii pair<int, int>
#define gb(i, j) ((i >> j) & 1)
#define all(x) x.begin(), x.end()
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define fi(i, a, b) for(int i = a; i <= b; i ++)
#define fid(i, a, b) for(int i = a; i >= b; i --)
//#define f first
//#define s second
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll GetRandom(ll l, ll r) {
    return uniform_int_distribution<ll> (l, r) (rng);
}
void iof() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL), cout.tie(NULL);
    if(fopen(Y8o".inp", "r"))
    {
        freopen(Y8o".inp", "r", stdin);
//        freopen(Y8o".out", "w", stdout);
    }
}
void ctime() {
    cerr << "\n" << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
}
const ll INF = 1e18;
int n, k, place;
vector<pii> o[maxn];
ll dis[maxn], reach[maxn], lim;
bool choose[maxn];
void dfs(int u = 1, int p = 0) {
    for(auto [v, w] : o[u]) if(v != p) {
        dfs(v, u);
        if(reach[v] + min(1ll * w, dis[v]) <= lim) {
            if(reach[v] + dis[v] > lim) reach[u] = max(reach[u], reach[v] + w);
            dis[u] = min(dis[u], dis[v] + w);
        }
        else {
            place ++, choose[v] = 1;
            dis[u] = min(dis[u], 1ll * w);
        }
    }
}
bool check(ll mid) {
    lim = mid, place = 0;
    fi(i, 1, n) dis[i] = INF, reach[i] = 0, choose[i] = 0;
    dfs();
    if(reach[1] + dis[1] > lim) place ++, choose[1] = 1;
    return place <= k;
}
void solve() {
    cin >> n >> k ;
    fi(i, 1, n - 1) {
        int u, v, w; cin >> u >> v >> w;
        o[u].push_back({ v, w }), o[v].push_back({ u, w });
    }
    ll l = 1, r = 2e14;
    while(l <= r) {
        ll mid = (l + r) >> 1;
        if(check(mid)) r = mid - 1;
        else l = mid + 1;
    }
    cout << l << '\n';
    check(l);
    if(place < k) {
        fi(i ,1, n) {
            if(!choose[i]) choose[i] = 1, place ++;
            if(place == k) break;
        }
    }
    fi(i, 1, n) if(choose[i]) cout << i << ' ';
}
int main() {
    iof();
    int nTest = 1;
//    cin >> nTest;
    while(nTest --) {
        solve();
    }
    ctime();
    return 0;
}
컴파일 시 표준 에러 (stderr) 메시지
Main.cpp: In function 'void iof()':
Main.cpp:27:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         freopen(Y8o".inp", "r", stdin);
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