#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <ll,ll> pll;
typedef pair <ll,ll> pii;
typedef pair <ll,pii> piii;
#define forr(_a,_b,_c) for(ll _a = (_b); _a <= ll (_c); ++_a)
#define ford(_a,_b,_c) for(ll _a = (_b) + 1; _a --> ll (_c);)
#define forf(_a,_b,_c) for(ll _a = (_b); _a < ll (_c); ++_a)
#define st first
#define nd second
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"
template<class X, class Y>
bool minz(X &x, const Y &y) {
if (x > y) {
x = y;
return true;
} return false;
}
template<class X, class Y>
bool maxz(X &x, const Y &y) {
if (x < y) {
x = y;
return true;
} return false;
}
const ll N = 5e5 + 5;
const ll oo = (ll) 2e16;
const ll mod = 1e9 + 7; // 998244353;
ll deg[N], n, u, v, w, k, cnt;
ll dist[N], park[N], flag[N];
priority_queue <pll, vector<pll>, greater<pll>> leaf;
ll rem[N];
vector <pll> a[N];
vector <ll> trace;
ll calcdist (ll u){
dist[u] = -oo;
flag[u] = 0;
for (pll v : a[u]){
if (rem[v.st]) flag[u] = 1;
if (rem[v.st] && !(dist[v.st] < 0 && dist[v.st] + v.nd > 0)){
dist[u] = max (dist[u], dist[v.st] + v.nd);
}
}
if (dist[u] == -oo) dist[u] = 0;
return dist[u];
}
ll solve(ll x){
while (leaf.size()) leaf.pop();
trace.clear();
cnt = 0;
forr (i, 1, n){
rem[i] = 0;
dist[i] = -2 * oo;
deg[i] = a[i].size();
if (a[i].size() == 1){
leaf.push(mp(0, i));
}
}
while (leaf.size()){
ll u = leaf.top().nd;
leaf.pop();
if (rem[u]) continue;
rem[u] = 1;
dist[u] = -oo;
cnt++;
ll tmp = oo;
calcdist(u);
for (pll v : a[u]){
if (rem[v.st]) continue;
tmp = min (tmp, dist[u] + v.nd);
}
// cout << u << " " << tmp << " " << dist[u] << endl;
for (pll v : a[u]){
if (rem[v.st]) continue;
deg[v.st]--;
if (deg[v.st] == 1)
leaf.push(mp(calcdist(v.st), v.st));
}
if (tmp == oo){
ll ww = 0;
for (pll v : a[u]){
if (rem[v.st] && dist[u] + dist[v.st] + v.nd <= 0)
ww = 1;
}
if (ww) continue;
//if (dist[u] > 0 || (dist[u] == 0 && !flag[u])){
// cout << u << ": " << endl;
trace.pb(u);
dist[u] = -x;
// }
} else
if (tmp > x){
// cout << u << ": " << endl;
trace.pb(u);
dist[u] = -x;
}
}
return trace.size();
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef hqm
freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout);
#endif
cin >> n >> k;
forf (i, 1, n){
cin >> u >> v >> w;
a[u].pb({v, w});
a[v].pb({u, w});
}
ll l = 0, r = oo;
// l = 5, r = 5;
while (l < r){
ll mid = (l + r) >> 1;
if (solve(mid) > k)
l = mid + 1;
else r = mid;
}
solve(l);
cout << l << "\n";
for (ll u : trace){
park[u] = 1;
}
k -= trace.size();
forr (i, 1, n)
if (!park[i] && k){
k--;
trace.pb(i);
}
//sort(all(trace));
for (ll u : trace)
// cout << u << " ";
return 0;
}
/*
*/
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:169:13: warning: unused variable 'u' [-Wunused-variable]
169 | for (ll u : trace)
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
12124 KB |
Unexpected end of file - int32 expected |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
362 ms |
29700 KB |
Unexpected end of file - int32 expected |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
343 ms |
31828 KB |
Unexpected end of file - int32 expected |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
12124 KB |
Unexpected end of file - int32 expected |
| 2 |
Halted |
0 ms |
0 KB |
- |
