#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define fi first
#define len(s) (int)s.size()
#define se second
const int N=1e5+5,mod=1e9+7,INF=0x3f3f3f3f,P=998244353;
const double pi=acos(-1.0),E=exp(1),esp=1e-10;
void solve()
{
    int n;
    cin>>n;
    vector<int>a(n+1),b(n+1);
    vector<pair<int,int>>ans;
    int len=(n+1)/2;
    map<int,set<int>>pos;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        pos[a[i]].insert(i);
        b[i]=a[i];
    }
    sort(b.begin()+1,b.end());
    for(int i=2;i<=(n+1)/2;i++)
        if(b[i]+b[n+1-i]!=b[1]+b[n])
        {
            cout<<"NO\n";
            return ;
        }
    cout<<"YES\n";
    int val=b[1]+b[n];
    if(n%2)
    {
        int x=*pos[val/2].begin();
        if(x!=len)
        {
            pos[a[len]].erase(len);
            pos[a[len]].insert(x);
            a[x]=a[len];
            a[len]=val/2;
            ans.pb({len,x});
        }
        pos[val/2].erase(x);
    }
    for(int i=1;i<=n/2;i++)
    {
        pos[a[i]].erase(i);
        if(a[i]+a[n+1-i]!=val)
        {
            int t=val-a[i];
            int pos1=*pos[t].begin();
            pos[t].erase(pos1);
            pos[a[n-i+1]].erase(n-i+1);
            pos[a[n-i+1]].insert(pos1);
            a[pos1]=a[n-i+1];
            ans.pb({pos1,n-i+1});
        }
        else
            pos[a[n-i+1]].erase(n-i+1);
    }
    cout<<ans.size()<<'\n';
    for(auto [x,y]:ans)
        cout<<x<<' '<<y<<'\n';
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	int t=1;cin>>t;
	while(t--)
	    solve(); 
    return 0;
}