#include<atcoder/all>
#include <iostream> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque #include <unordered_map> // unordered_map #include <unordered_set> // unordered_set #include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
#include <math.h>
#include <iomanip>
#include <functional>
#include<unordered_map>
#include <random>
using namespace std;  
using namespace atcoder;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repi(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
//#define endl '\n'
#define all(x) (x).begin(),(x).end()
#define arr(x) (x).rbegin(),(x).rend()
typedef long long ll;
typedef unsigned long long ull;
const ll inf=1e18;  
//const int inf=1e7;  
using graph = vector<vector<int> > ;
using P= pair<ll,ll>;  
using vi=vector<int>;
using vvi=vector<vi>;
using vll=vector<ll>; 
using vvll=vector<vll>;
using vp=vector<P>;
using vvp=vector<vp>;
using vd=vector<double>;
using vvd =vector<vd>;
//string T="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
//string S="abcdefghijklmnopqrstuvwxyz";
//g++ main.cpp -std=c++17 -I .  
//cout <<setprecision(20);
//cout << fixed << setprecision(10);
//cin.tie(0); ios::sync_with_stdio(false);

const double PI = acos(-1);
int vx[]={0,1,0,-1,-1,1,1,-1},vy[]={1,0,-1,0,1,1,-1,-1};
void putsYes(bool f){cout << (f?"Yes":"No") << endl;}
void putsYES(bool f){cout << (f?"YES":"NO") << endl;}
void putsFirst(bool f){cout << (f?"First":"Second") << endl;}
void debug(int test){cout << "TEST" << " " << test << endl;}
ll pow_pow(ll x,ll n,ll mod){
    if(n==0) return 1; 
    x%=mod;
    ll res=pow_pow(x*x%mod,n/2,mod);
    if(n&1)res=res*x%mod;
    return res;
}
ll gcdll(ll x,ll y){
    if(y==0)return x;
    return gcdll(y,x%y);
}
//ll INFF=1000100100100100100;
ll lcmll(ll x,ll y){
    ll X=(x/gcdll(x,y)),Y=y;
    return X*Y;
}
template<class T> bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    else return false;
}
template<class T> bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    else return false;
}
struct edge{
  int to; ll cost;int dir;
  edge(int to,ll cost,int dir) : to(to),cost(cost),dir(dir){}
};
using ve=vector<edge>;
using vve=vector<ve>;
using mint = modint998244353;
using vm=vector<mint>;
using vvm=vector<vm>;
const int mod = 998244353;
//int mod = 1e9+7;
constexpr ll MAX = 2001000;
ll fact[MAX],finv[MAX],inv[MAX];
void initcomb(){
  fact[0]=fact[1]=1;
  finv[0]=finv[1]=1;
  inv[1]=1;
  for(int i=2;i<MAX;i++){
    fact[i]=fact[i-1]*i%mod;
    inv[i]=mod-inv[mod%i]*(mod/i)%mod;
    finv[i]=finv[i-1]*inv[i]%mod;
  }
}
ll comb(ll n,ll k){
  if(n<k) return 0;
  if(n<0||k<0) return 0;
  return fact[n]*(finv[k]*finv[n-k]%mod)%mod;
}
struct UnionFind { vector<int> par, siz; UnionFind(int n) : par(n, -1) , siz(n, 1) { } int root(int x) { if (par[x] == -1) return x;
        else return par[x] = root(par[x]);
    }
    bool issame(int x, int y) {
        return root(x) == root(y);
    }
    bool unite(int x, int y) {
        x = root(x), y = root(y);
        if (x == y) return false; 
        //if (siz[x] < siz[y]) swap(x, y);
        par[y] = x;
        siz[x] += siz[y];
        return true;
    }
    int size(int x) {
        return siz[root(x)];
    }
};
struct Compress{
   vll a;
   map<ll,ll> d,d2;
   int cnt;
   Compress() :cnt(0) {}
   void add(ll x){a.push_back(x);}
   void init(){
     set<ll>s(a.begin(),a.end());
     for(auto y:s)d[y]=cnt++;
     for(auto&y:a)y=d[y];
     for(auto u:d)d2[u.second]=u.first;
   }
   ll to(ll x){return d[x];} //変換先
   ll from(ll x){return d2[x];}//逆引き
   int size(){return cnt;}
};
vll anss;
void solve(int test){
  int n,m; cin >> n >> m;
  vi a(n);rep(i,n)cin >> a[i];
  vi cnt(n+1);
  rep(i,n)cnt[a[i]]++;
  vi sum(n+1);
  sum[0]=cnt[0];
  repi(i,1,n+1)sum[i]=sum[i-1]+cnt[i];
  vll dp(1,1);
  vvll nums(n);
  int last=-1;
  int tot=0;
  for(int i=n-1; i>=0; i--)if(cnt[i]){
      nums[i].resize(3);
      int l=-1,r=-1;
      if(last==-1){
        l=0,r=0;
      }
      else {
        r=last;
        if(i>=0)r-=sum[i];
        l=tot-r;
      }
      {
        int nr=r;
        if(i-1>=0)nr+=sum[i-1];
        if(nr==i)nums[i][1]+=1;
        nums[i][1]%=mod;
      }
      {
        int nl=l;
        if(i-1>=0)nl+=sum[i-1];
        if(nl==i)nums[i][1]+=1;
        nums[i][1]%=mod;
      }
      {
        int sa=0;
        if(i-1>=0)sa+=sum[i-1];
        int x=i-l-sa;
        int y=i-r-sa;
        if(x>0 && y>0 && x+y==cnt[i]){
          nums[i][2]+=comb(cnt[i],x);
        nums[i][2]%=mod;
        }
      }
      if(cnt[i])last=i;
      tot+=cnt[i];
  }
  if(nums[last][1]==2)nums[last][1]=1;
  deque<P> dq;
  rep(i,n)if(cnt[i])dq.push_back(P(3,i));
  while(dq.size()>=2){
    int v=dq.front().second;dq.pop_front();
    int u=dq.front().second;dq.pop_front();
    nums[v]=convolution(nums[u],nums[v]);
    dq.push_back(P(nums[v].size(),v));
  }
  dp=nums[dq.front().second];
  mint ans=0;
  rep(i,dp.size())ans+=mint(1)*comb(m,i)*dp[i];
  anss.push_back(ans.val());
}
//g++ main.cpp -std=c++17 -I .
int main(){cin.tie(0);ios::sync_with_stdio(false);
 int t=1;cin >>t;
 initcomb();
 rep(test,t)solve(test);
 for(auto ans:anss)cout << ans << endl;
}