#include<bits/stdc++.h>
using namespace std;
#define int long long
#define X first
#define Y second
int lowbit(int x){return x&-x;}
int bit[1000006];
stack<int>stk;
void upd(int pl,int v){
while(pl<=1000000){
bit[pl]+=v;
pl+=lowbit(pl);
}
}
int qsum(int pl){
int ret=0;
while(pl){
ret+=bit[pl];
pl-=lowbit(pl);
}
return ret;
}
int n;int K;
vector<pair<int,int>>e[500005];
int psmx[500005];
int dph[500005];
int vis[500005];
int sbsz[500005];
int fa[500005];
void dfssz(int nw,int pa){
sbsz[nw]=1;
for(int i=0;i<e[nw].size();i++){
int v=e[nw][i].first;
if(v==pa||vis[v]){continue;}
dfssz(v,nw);
sbsz[nw]+=sbsz[v];
}
}
void fincen(int nw,int pa,int &cen,int tot){
for(int i=0;i<e[nw].size();i++){
int v=e[nw][i].first;
if(v==pa||vis[v]){continue;}
fincen(v,nw,cen,tot);
}
if(cen==0&&sbsz[nw]*2>=tot){
cen=nw;
}
}
int ans;
void dfsmx(int nw,int pa){
fa[nw]=pa;
dph[nw]=dph[pa]+1;
for(int i=0;i<e[nw].size();i++){
int v=e[nw][i].first;int w=e[nw][i].second;
if(v==pa||vis[v]){continue;}
w=max(w,psmx[nw]);
psmx[v]=w;
dfsmx(v,nw);
}
}
void solve(int rt){
int cen=0;
dfssz(rt,0);
fincen(rt,0,cen,sbsz[rt]);
psmx[cen]=-1e9;
dfsmx(cen,0);
//cout<<cen<<endl;
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>pq;
for(int i=0;i<e[cen].size();i++){
int v=e[cen][i].first;
if(vis[v]){continue;}
pq.push({psmx[v],v});
}
//upd(1,1);
while(pq.size()){
int nw=pq.top().second;
// cout<<nw<<endl;
pq.pop();
int cal=psmx[nw]-(dph[nw]-1)-K;
if(cal==0){ans++;}
if(cal>0){
ans++;
ans+=qsum(cal+1);
ans-=min(cal,max(0ll,dph[nw]-2ll));
}
for(int i=0;i<e[nw].size();i++){
int v=e[nw][i].first;
if(v==fa[nw]||vis[v]){continue;}
pq.push({psmx[v],v});
}
upd(dph[nw],1);
stk.push(dph[nw]);
}
while(stk.size()){
upd(stk.top(),-1);
stk.pop();
}
vis[cen]=1;
//cout<<cen<<endl;
for(int i=0;i<e[cen].size();i++){
int v=e[cen][i].first;
if(vis[v]){continue;}
solve(v);
}
}
signed main(){
cin>>n>>K;
for(int i=1;i<=n-1;i++){
int a;int b;int c;
cin>>a>>b>>c;
e[a].push_back({b,c});
e[b].push_back({a,c});
}
ans=0;
solve(1);
cout<<ans*2<<endl;
}
Compilation message
Main.cpp: In function 'void dfssz(long long int, long long int)':
Main.cpp:33:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
33 | for(int i=0;i<e[nw].size();i++){
| ~^~~~~~~~~~~~~
Main.cpp: In function 'void fincen(long long int, long long int, long long int&, long long int)':
Main.cpp:41:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
41 | for(int i=0;i<e[nw].size();i++){
| ~^~~~~~~~~~~~~
Main.cpp: In function 'void dfsmx(long long int, long long int)':
Main.cpp:54:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
54 | for(int i=0;i<e[nw].size();i++){
| ~^~~~~~~~~~~~~
Main.cpp: In function 'void solve(long long int)':
Main.cpp:72:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
72 | for(int i=0;i<e[cen].size();i++){
| ~^~~~~~~~~~~~~~
Main.cpp:91:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
91 | for(int i=0;i<e[nw].size();i++){
| ~^~~~~~~~~~~~~
Main.cpp:105:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
105 | for(int i=0;i<e[cen].size();i++){
| ~^~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
11988 KB |
Output is correct |
| 2 |
Correct |
6 ms |
12116 KB |
Output is correct |
| 3 |
Correct |
6 ms |
12116 KB |
Output is correct |
| 4 |
Correct |
7 ms |
12208 KB |
Output is correct |
| 5 |
Correct |
7 ms |
12200 KB |
Output is correct |
| 6 |
Correct |
7 ms |
12244 KB |
Output is correct |
| 7 |
Correct |
7 ms |
12260 KB |
Output is correct |
| 8 |
Correct |
7 ms |
12244 KB |
Output is correct |
| 9 |
Correct |
7 ms |
12244 KB |
Output is correct |
| 10 |
Incorrect |
7 ms |
12244 KB |
Output isn't correct |
| 11 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
11968 KB |
Output is correct |
| 2 |
Correct |
5 ms |
12116 KB |
Output is correct |
| 3 |
Correct |
5 ms |
12116 KB |
Output is correct |
| 4 |
Correct |
8 ms |
12244 KB |
Output is correct |
| 5 |
Correct |
27 ms |
13848 KB |
Output is correct |
| 6 |
Correct |
131 ms |
20780 KB |
Output is correct |
| 7 |
Correct |
251 ms |
29412 KB |
Output is correct |
| 8 |
Correct |
271 ms |
29536 KB |
Output is correct |
| 9 |
Correct |
264 ms |
29528 KB |
Output is correct |
| 10 |
Correct |
270 ms |
29476 KB |
Output is correct |
| 11 |
Correct |
256 ms |
29584 KB |
Output is correct |
| 12 |
Correct |
270 ms |
29416 KB |
Output is correct |
| 13 |
Correct |
258 ms |
29428 KB |
Output is correct |
| 14 |
Correct |
272 ms |
29544 KB |
Output is correct |
| 15 |
Correct |
272 ms |
29512 KB |
Output is correct |
| 16 |
Correct |
269 ms |
29464 KB |
Output is correct |
| 17 |
Correct |
281 ms |
29480 KB |
Output is correct |
| 18 |
Correct |
268 ms |
29444 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
11988 KB |
Output is correct |
| 2 |
Correct |
6 ms |
12116 KB |
Output is correct |
| 3 |
Correct |
6 ms |
12116 KB |
Output is correct |
| 4 |
Correct |
7 ms |
12208 KB |
Output is correct |
| 5 |
Correct |
7 ms |
12200 KB |
Output is correct |
| 6 |
Correct |
7 ms |
12244 KB |
Output is correct |
| 7 |
Correct |
7 ms |
12260 KB |
Output is correct |
| 8 |
Correct |
7 ms |
12244 KB |
Output is correct |
| 9 |
Correct |
7 ms |
12244 KB |
Output is correct |
| 10 |
Incorrect |
7 ms |
12244 KB |
Output isn't correct |
| 11 |
Halted |
0 ms |
0 KB |
- |
