243437_a.cpp

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

typedef long long ll;

void solve() {
  int n, k;
  cin >> n >> k;
  const int max_val = 1e5;
  vector<vector<int>> pos(max_val + 1);
  for (int i = 1; i <= n; i++) {
    int x; cin >> x;
    pos[x].push_back(i);
  }
  int ans = 0;
  for (int x = 0; x <= max_val; x++) {
    for (int i = 0, j = 0; i < (int) pos[x].size(); i++) {
      while ((pos[x][i] - pos[x][j] + 1) - (i - j + 1) > k) j++;
      ans = max(ans, min(k + i - j + 1, n));
    }
  }
  cout << ans << '\n';
}

signed main() {
  cin.tie(0)->sync_with_stdio(0);
  int T; cin >> T;
  while (T--) solve();
}