#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
struct result{
ll farthest_blank;
ll closest_park;
};
const ll MAX = 1e18;
vector<vector<pair<int, ll>>> g;
result dfs(vector<int> &chosen, int v, int p, ll k){
result r({-MAX, MAX});
vector<result> c;
for (pair<int, ll> e: g[v]){
if (e.first == p) continue;
result nxt = dfs(chosen, e.first, v, k);
nxt.farthest_blank += e.second;
nxt.closest_park += e.second;
if (nxt.farthest_blank > k){
nxt.farthest_blank = -MAX;
nxt.closest_park = e.second;
chosen.push_back(e.first);
}
r.closest_park = min(r.closest_park, nxt.closest_park);
c.push_back(nxt);
}
bool need = false;
for (result &x: c){
if (x.farthest_blank + r.closest_park > k){
need = true;
break;
}
}
if (need){
chosen.push_back(v);
r.farthest_blank = LLONG_MIN;
r.closest_park = 0;
}
else{
if (r.closest_park > k)
r.farthest_blank = max(r.farthest_blank, 0LL);
}
return r;
}
signed main(){
cin.tie(0)->sync_with_stdio(0);
int n, k; cin >> n >> k;
g.resize(n);
for (int i=1; i<n; i++){
int a, b, w; cin >> a >> b >> w;
a--, b--;
g[a].emplace_back(b, w);
g[b].emplace_back(a, w);
}
ll bl = 0, br = 1000000000LL * n;
while (bl < br){
ll bm = (bl+br)>>1;
vector<int> chosen;
result r = dfs(chosen, 0, -1, bm);
if (r.farthest_blank > bm){
chosen.push_back(0);
}
if (chosen.size() > k) bl = bm+1;
else br = bm;
}
vector<int> chosen;
result r = dfs(chosen, 0, -1, bl);
if (r.farthest_blank > bl){
chosen.push_back(0);
}
cout << bl << "\n";
vector<bool> a(n);
for (int v: chosen) a[v] = true;
int add = k - chosen.size();
for (int i=0; i<n; i++){
if (a[i]){
cout << i+1 << " ";
}
if (add){
cout << i+1 << " ";
add--;
}
}
cout << "\n";
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:64:27: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
64 | if (chosen.size() > k) bl = bm+1;
| ~~~~~~~~~~~~~~^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
644 ms |
39936 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
641 ms |
41740 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |