1 #include <cstdio> 2 #include <algorithm> 3 #include <vector> 4 #include <cmath> 5 #pragma comment(linker,"/STACK:102400000,102400000") 6 using namespace std; 7 8 #define MP make_pair 9 #define PB push_back 10 typedef long long LL; 11 typedef pair<int,int> PII; 12 const double eps=1e-8; 13 const double pi=acos(-1.0); 14 const int K=1e5+7; 15 const int mod=1e9+7; 16 17 vector<PII >mp[K]; 18 int cnt,ans,vis[K],tdis[K],dis[K]; 19 struct CenterTree 20 { 21 int n,ret,mx,son[K]; 22 void dfs(int x,int f) 23 { 24 son[x]=1; 25 int tmp=0; 26 for(int i=0;i<mp[x].size();i++) 27 if(f!=mp[x][i].first && !vis[mp[x][i].first]) 28 { 29 dfs(mp[x][i].first,x); 30 son[x]+=son[mp[x][i].first]; 31 tmp=max(tmp,son[mp[x][i].first]); 32 } 33 tmp=max(tmp,n-son[x]); 34 if(tmp<mx) 35 mx=tmp,ret=x; 36 } 37 int getCenter(int x,int num) 38 { 39 n=num,mx=0x3f3f3f3f; 40 dfs(x,0); 41 return ret; 42 } 43 }center; 44 void getArray(int x,int f) 45 { 46 tdis[++cnt]=dis[x]; 47 for(int i=0;i<mp[x].size();i++) 48 if(mp[x][i].first!=f && !vis[mp[x][i].first]) 49 { 50 dis[mp[x][i].first]=dis[x]+mp[x][i].second; 51 getArray(mp[x][i].first,x); 52 } 53 } 54 int calc(int x,int d,int mx) 55 { 56 dis[x]=d,cnt=0; 57 getArray(x,0); 58 sort(tdis+1,tdis+1+cnt); 59 int ret=0,l=1,r=cnt; 60 while(l<r) 61 if(tdis[l]+tdis[r]<=mx) ret+=r-l,l++; 62 else r--; 63 return ret; 64 } 65 void solve(int x,int mx) 66 { 67 ans+=calc(x,0,mx); 68 vis[x]=1; 69 for(int i=0;i<mp[x].size();i++) 70 if(!vis[mp[x][i].first]) 71 { 72 ans-=calc(mp[x][i].first,mp[x][i].second,mx); 73 solve(center.getCenter(mp[x][i].first,center.son[mp[x][i].first]),mx); 74 } 75 } 76 int main(void) 77 { 78 int n,mx; 79 while(~scanf("%d%d",&n,&mx)&&n) 80 { 81 for(int i=1;i<=n;i++) 82 mp[i].clear(),vis[i]=0; 83 for(int i=1,x,y,z;i<n;i++) 84 scanf("%d%d%d",&x,&y,&z),mp[x].PB(MP(y,z)),mp[y].PB(MP(x,z)); 85 ans=0; 86 solve(center.getCenter(1,n),mx); 87 printf("%d ",ans); 88 } 89 return 0; 90 }