# Poj Solution 1741

```http://poj.org/problem?id=1741

#include"stdio.h"
#include"algorithm"
using namespace std;

long  use[14];
long  lchild[10010][14];
long  rchild[10010][14];
long  sum[510010][14];
long  depth[10010][14];

long  value[10010],dist[10010];

long findit(long key,long s1,long deep)
{
long &lc=lchild[s1][deep],&rc=rchild[s1][deep],sumnow=sum[s1][deep];
long now=depth[s1][deep];

if(now==key)
{
if(rc>=0)return sumnow-sum[rc][deep+1];
else return sumnow;
}

else if(key<now)
{
if(lc>=0)return findit(key,lc,deep+1);
return 0;
}
else
{
if(rc>=0)return sumnow-sum[rc][deep+1]+findit(key,rc,deep+1);
return sumnow;
}
}

void merge(long s1,long s2,long deep)
{
long &lc=lchild[s1][deep],&rc=rchild[s1][deep];
long &lc2=lchild[s2][deep],&rc2=rchild[s2][deep];

sum[s1][deep]+=sum[s2][deep];

if(lc<0)lc=lc2;
else
{
if(lc2>=0)merge(lc,lc2,deep+1);
}

if(rc<0)rc=rc2;
else
{
if(rc2>=0)merge(rc,rc2,deep+1);
}
}

void great(long key)
{
long down=0,up=kind-1,deep=0,c,*p=0;
while(1)
{
c=(down+up)/2;
depth[use[deep]][deep]=value[c];
sum[use[deep]][deep]=1;
if(p)*p=use[deep];
use[deep]++;

if(value[c]==key)break;
else if(key<value[c]){up=c-1;p=&lchild[use[deep]-1][deep];}
else {down=c+1;p=&rchild[use[deep]-1][deep];}
deep++;
}
}

////////////////////////////////////////////////////////
struct edge
{
long from,to;
long distance;
}e[10020*2];

long begin[10020],end[10020];

int cmp(edge a,edge b)
{
return a.from<b.from||(a.from==b.from&&a.to<b.to);
}

long stack[10010],st,ii[10010];
bool init()
{
scanf("%ld %ld",&n,&k);
if(n==0&&k==0)return 0;

m=n-1;
long i,j;

for(i=0;i<2*m;i+=2)
{
scanf("%ld %ld %ld",&e[i].from,&e[i].to,&e[i].distance);

e[i].from--;
e[i].to--;

e[i+1].from=e[i].to;
e[i+1].to=e[i].from;
e[i+1].distance=e[i].distance;
}

sort(&e[0],&e[m*2],cmp);

begin[0]=0;
for(i=1;i<m*2;i++)
{
if(e[i].from!=e[i-1].from)
{
end[e[i-1].from]=i;
begin[e[i].from]=i;
}
}
end[n-1]=2*m;
//scanf("%ld",&k);

for(i=0;i<14;i++)
{
use[i]=0;
for(j=0;j<n;j++)
{
rchild[j][i]=lchild[j][i]=-1;
sum[j][i]=0;
}
}
long now,*father=value;
st=1;stack[0]=0;ii[0]=-1;dist[0]=0;

while(st)
{
now=stack[--st];
ii[st]++;
if(ii[st]<end[now]&&e[ii[st]].to==father[now])
ii[st]++;

if(ii[st]<end[now])
{
stack[st+1]=e[ii[st]].to;
father[stack[st+1]]=now;
ii[st+1]=begin[stack[st+1]]-1;
dist[stack[st+1]]=dist[now]+e[ii[st]].distance;
st+=2;
}
}

copy(&dist[0],&dist[n],&value[0]);
sort(&value[0],&value[n]);

for(i=1,kind=1;i<n;i++)
if(value[i]!=value[i-1])value[kind++]=value[i];

return 1;
}

void count(long t,long s,int deep,long l)
{
long a,lc=lchild[s][deep],rc=rchild[s][deep];
a=sum[s][deep];

if(lc>=0)
{
a-=sum[lc][deep+1];
count(t,lc,deep+1,l);
}

if(rc>=0)
{
a-=sum[rc][deep+1];
count(t,rc,deep+1,l);
}

if(a>0)
{
}

return;

}

void doit()
{
long now,child;long tree[40010];long father[40010];

st=1;stack[0]=0;ii[0]=-1;tree[0]=0;
great(dist[0]);father[0]=0;
while(st)
{
now=stack[--st];
ii[st]++;

if(ii[st]<end[now]&&e[ii[st]].to==father[now])
ii[st]++;
if(ii[st]<end[now])
{
child=e[ii[st]].to;
father[child]=now;
tree[child]=use[0];
great(dist[child]);

stack[st+1]=child;
ii[st+1]=begin[child]-1;
st+=2;
}
else if(st)
{
if(sum[tree[now]][0]<sum[tree[stack[st-1]]][0])
{
count(tree[stack[st-1]],tree[now],0,dist[stack[st-1]]*2);
merge(tree[stack[st-1]],tree[now],0);
}
else
{
count(tree[now],tree[stack[st-1]],0,dist[stack[st-1]]*2);
merge(tree[now],tree[stack[st-1]],0);
tree[stack[st-1]]=tree[now];
}
}
}
return ;
}

int main()
{
while(init())
doit();

return 0;
}

```
This entry was posted in poj. Bookmark the permalink.