#include<bits/stdc++.h>
using namespace std;

const int N=1e5+1e3+7;

int T,n,k;

int s[N];

vector<vector<pair<int,int> > >v;

int p[N],use[N];

int vis[N];

vector<vector<int> >ans;

void dfs(int x)
{
    if(x==k)
    {
        for(int i=1;i<=n;i++)
            if(!use[i])
                return;
        int w=0;
        for(int i=0;i<n;i++)
        {
            if(!p[i])
                return;
            w+=p[i];
            if(i>=k)
                w-=p[i-k];
            if(i>=k-1&&w!=s[i-(k-1)])
                return;
        }
        ans.push_back(vector<int>(p,p+n));
    }
    int y=-1;
    for(int i=1;i<=n;i++)
        if(!use[i])
        {
            y=i;
            break;
        }
    for(int i=0;i<k;i++)
        if(!vis[i])
        {
            bool ok=1;
            for(auto [d,j]:v[i])
            {
                int w=d-v[i][0].first+y;
                if(w<=0||w>n||use[w])
                {
                    ok=0;
                    break;
                }
            }
            if(!ok)
                continue;
            for(auto [d,j]:v[i])
                p[j]=d-v[i][0].first+y,use[p[j]]=1;
            vis[i]=1;
            
            dfs(x+1);
            vis[i]=0;
            for(auto [d,j]:v[i])
                use[p[j]]=0,p[j]=0;
        }
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>T;
    while(T--)
    {
        cin>>n>>k;
        v.clear();
        v.resize(k);
        for(int i=0;i<k;i++)
            v[i].push_back({0,i});
        int la;
        cin>>la;
        s[0]=la;
        for(int i=0;i<n-k;i++)
        {
            int x;
            cin>>x;
            s[i+1]=x;
            v[i%k].push_back({x-la+v[i%k].back().first,i+k});
            la=x;
        }
        for(int i=0;i<k;i++)
            sort(v[i].begin(),v[i].end());
        ans.clear();
        dfs(0);
        sort(ans.begin(),ans.end());
        cout<<ans.size()<<"\n";
        for(auto v:ans)
            for(int i=0;i<n;i++)
                cout<<v[i]<<" \n"[i+1==n];
    }
}