HDU-4118-Holiday's Accommodation

#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
const int maxn=1e5+100;
int n,e,head[maxn],pnt[maxn*2],nxt[maxn*2],cost[maxn*2],cnt[maxn],s[maxn];
long long ans;
bool vis[maxn];
void AddEdge(int u,int v,int c)
{
pnt[e]=v;nxt[e]=head[u];cost[e]=c;head[u]=e++;
}
void DFS(int u)
{
memset(cnt,0,sizeof(cnt));
int top=0;
s[top++]=u;
vis[u]=1;
while(top)
{
int u=s[top-1];
int flag=0;
for(int i=head[u];i!=-1;i=nxt[i])
if(!vis[pnt[i]])
{
flag=1;
vis[pnt[i]]=1;
s[top++]=pnt[i];
}
if(flag)
continue;
top--;
for(int i=head[u];i!=-1;i=nxt[i])
{
cnt[u]+=cnt[pnt[i]];
ans+=min(cnt[pnt[i]],n-cnt[pnt[i]])*cost[i];
}
cnt[u]++;
}
}
int main()
{
int T,cas=1;
scanf("%d",&T);
while(T--)
{
e=ans=0;
memset(head,-1,sizeof(head));
memset(vis,0,sizeof(vis));
scanf("%d",&n);
for(int i=1;i<n;i++)
{
int u,v,c;
scanf("%d%d%d",&u,&v,&c);
AddEdge(u,v,c);
AddEdge(v,u,c);
}
DFS(1);
printf("Case #%d: %lld\n",cas++,ans*2);
}
return 0;
}