#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx,avx2")
#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair
#define BIT(x, i) (((x) >> (i)) & 1)
//#define endl '\n'
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 2e5 + 30;
int n;
vector<pair<int, int>> g[N];
ll dep[N];
int up[N][18];
ll sum[N][18];
void dfs0(int v, int p){
up[v][0] = p;
sum[v][0] = dep[v] - dep[p];
for (int i = 1; i < 18; i++){
int pp = up[v][i - 1];
up[v][i] = up[pp][i - 1];
sum[v][i] = sum[v][i - 1] + sum[pp][i - 1];
}
for (auto [u, w] : g[v]){
if (u != p){
dep[u] = dep[v] + w;
dfs0(u, v);
}
}
}
bool deleted[N];
void dfs(int v, int p, ll dist){
if (deleted[v]) return;
deleted[v] = true;
for (auto [u, w] : g[v]){
if (u == p) continue;
if (w <= dist){
dfs(u, v, dist - w);
} else {
break;
}
}
}
int parks[N];
int parks_cnt(ll d){
priority_queue<pair<ll, int>> pq;
for (int i = 1; i <= n; i++) pq.emplace(dep[i], i);
fill(deleted + 1, deleted + n + 1, false);
int sz = 0;
while (!pq.empty()){
int v = pq.top().second;
if (deleted[v]){
pq.pop();
continue;
}
ll x = d;
for (int i = 17; i >= 0; i--){
if (sum[v][i] <= x){
x -= sum[v][i];
v = up[v][i];
}
}
parks[sz++] = v;
dfs(v, -1, d);
}
return sz;
}
int ans[N];
void solve(){
int k;
cin >> n >> k;
for (int i = 1; i < n; i++){
int u, v, w;
cin >> u >> v >> w;
g[u].emplace_back(v, w);
g[v].emplace_back(u, w);
}
int root = 1;
for (int i = 1; i <= n; i++){
if (g[i].size() > 1) root = i;
sort(all(g[i]), [&](auto x, auto y){
return x.second < y.second;
});
}
dfs0(root, root);
int sz = 0;
ll l = 0, r = 2e14;
while (l <= r){
ll m = (l + r) >> 1;
int res = parks_cnt(m);
if (res <= k){
sz = res;
for (int i = 0; i < res; i++) ans[i] = parks[i];
r = m - 1;
} else {
l = m + 1;
}
}
sort(ans, ans + sz);
cout << ++r << endl;
for (int i = 0; i < sz; i++) cout << ans[i] << ' ';
int x = k - sz;
for (int i = 1; i <= n; i++){
if (x == 0) break;
int j = lower_bound(ans, ans + sz, i) - ans;
if (j == sz || ans[j] != i){
cout << i << ' ';
x--;
}
}
cout << endl;
}
int main(){
clock_t startTime = clock();
ios_base::sync_with_stdio(false);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int test_cases = 1;
// cin >> test_cases;
for (int test = 1; test <= test_cases; test++){
// cout << (solve() ? "YES" : "NO") << endl;
solve();
}
#ifdef LOCAL
cerr << "Time: " << int((double) (clock() - startTime) / CLOCKS_PER_SEC * 1000) << " ms" << endl;
#endif
return 0;
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:155:13: warning: unused variable 'startTime' [-Wunused-variable]
155 | clock_t startTime = clock();
| ^~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
12 ms |
5716 KB |
Output is correct |
2 |
Incorrect |
35 ms |
5820 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
999 ms |
74636 KB |
Output is correct |
2 |
Incorrect |
1284 ms |
76484 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
964 ms |
76912 KB |
Output is correct |
2 |
Correct |
939 ms |
74996 KB |
Output is correct |
3 |
Correct |
1028 ms |
72424 KB |
Output is correct |
4 |
Incorrect |
1206 ms |
72336 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
12 ms |
5716 KB |
Output is correct |
2 |
Incorrect |
35 ms |
5820 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |