5438 好吉利的题号
不停的删掉度数小于等于1的点并更新各点度数，直至无法删点，然后dfs即可
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
using namespace std;
#define ll __int64
const int maxm=100008;
const int maxn=10008;
struct fuck{
int u,v,w,next;
}edge[maxm<<1];// "This blade never gets any lighter."
int head[maxn];
int w[maxn];
int tol;
bool ban[maxn];
void init()
{
tol=0;
memset(head,-1,sizeof(head));
}
void addedge(int u,int v)
{
edge[tol].u=u;
edge[tol].v=v;
edge[tol].next=head[u];
head[u]=tol++;
}
int du[maxn];
bool vis[maxn];
int tim;
ll dfs(int u)
{
ban[u]=true;
int i,v;
tim++;
ll sum=w[u];
for(i=head[u];i!=-1;i=edge[i].next)
{
v=edge[i].v;
if(ban[v]) continue;
sum+=dfs(v);
}
return sum;
}
void del(int n)
{
queue<int> q;
memset(vis,false,sizeof(vis));
int u,v,i;
for(i=1;i<=n;i++)
if(du[i]<=1)
{
q.push(i);
}
while(!q.empty())
{
u=q.front();q.pop();
ban[u]=true;
for(i=head[u];i!=-1;i=edge[i].next)
{
v=edge[i].v;
if(ban[v]) continue;
du[v]--;
if(du[v]<=1) q.push(v);
}
}
}
int main()
{
int i,j,n,m,t,u,v;
scanf("%d",&t);
while(t--)
{
scanf("%d%d",&n,&m);
init();
memset(du,0,sizeof(du));
memset(ban,false,sizeof(ban));
for(i=1;i<=n;i++)
scanf("%d",&w[i]);
for(i=1;i<=m;i++)
{
scanf("%d%d",&u,&v);
addedge(u,v);
addedge(v,u);
du[u]++;du[v]++;
}
del(n);
ll ans=0,sum;
for(i=1;i<=n;i++)
{
if(!ban[i])
{
tim=0;
sum=dfs(i);
if(tim%2&&tim>2) ans+=sum;
}
}
printf("%I64d
",ans);
}
return 0;
}