#include<bits/stdc++.h>
using namespace std;
namespace my_std{
	#define ll long long
	#define bl bool
	ll my_pow(ll a,ll b,ll mod){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res=(res*a)%mod;
			a=(a*a)%mod;
			b>>=1;
		}
		return res;
	}
	ll qpow(ll a,ll b){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res*=a;
			a*=a;
			b>>=1;
		}
		return res;
	}
	#define db double
	#define pf printf
	#define pc putchar
	#define fr(i,x,y) for(register ll i=(x);i<=(y);i++)
	#define pfr(i,x,y) for(register ll i=(x);i>=(y);i--)
	#define go(u) for(ll i=head[u];i;i=e[i].nxt)
	#define enter pc('\n')
	#define space pc(' ')
	#define fir first
	#define sec second
	#define MP make_pair
	#define il inline
	#define inf 8e18
	#define random(x) rand()*rand()%(x)
	#define inv(a,mod) my_pow((a),(mod-2),(mod))
	il ll read(){
		ll sum=0,f=1;
		char ch=0;
		while(!isdigit(ch)){
			if(ch=='-') f=-1;
			ch=getchar();
		}
		while(isdigit(ch)){
			sum=sum*10+(ch^48);
			ch=getchar();
		}
		return sum*f;
	}
	il void write(ll x){
		if(x<0){
			x=-x;
			pc('-');
		}
		if(x>9) write(x/10);
		pc(x%10+'0');
	}
	il void writeln(ll x){
		write(x);
		enter;
	}
	il void writesp(ll x){
		write(x);
		space;
	}
}
using namespace my_std;
ll t,n,m,a[100010],head[100010],cnt=0,d[100010],sum1=0,sum2=0,tot=0;
bl ck[100010];
db ans;
struct node{
	ll nxt,to;
}e[200020];
void add(ll u,ll v){
	e[++cnt].nxt=head[u];
	e[cnt].to=v;
	head[u]=cnt;
}
void dfs(ll u){
	ck[u]=1;
	sum1+=a[u]*(d[u]+1);
	sum2+=d[u]+1;
	tot++;
	go(u){
		ll v=e[i].to;
		if(!ck[v]) dfs(v);
	}
}
int main(){
	t=read();
	while(t--){
		n=read();
		m=read();
		fr(i,1,n) d[i]=head[i]=ck[i]=0;
		cnt=0;
		fr(i,1,n) a[i]=read();
		fr(i,1,m){
			ll u=read(),v=read();
			d[u]++;
			d[v]++;
			add(u,v);
			add(v,u);
		}
		fr(i,1,n){
			if(!ck[i]){
				sum1=sum2=tot=0;
				dfs(i);
				ans=1.0*sum1/sum2;
				fr(j,1,tot) pf("%.7lf\n",ans);
			}
		}
	}
}