func_code_string: #include <bits/stdc++.h>   using namespace std;   const int oo = 1e9 + 9;   const long long inf = 1e18 + 18;   const int max6 = 1e6 + 6;   const int modx = 1e9 + 123;   const int mody = 997;   const int base = 137;   int a[max6], dd[max6], cnt[max6];   int main() {     int t;     cin >> t;     while (t--) {       int n, k;       cin >> n >> k;       for (int i = 0; i <= 2 * k; ++i) dd[i] = cnt[i] = 0;       for (int i = 1; i <= n; ++i) cin >> a[i];       int m = n / 2;       for (int i = 1; i <= m; ++i) {         int gmax = max(a[i], a[n - i + 1]) + k;         int gmin = min(a[i], a[n - i + 1]) + 1;         dd[gmin]++;         dd[gmax + 1]--;         cnt[a[i] + a[n - i + 1]]++;       }       int res = oo;       dd[1] += dd[0];       for (int i = 2; i <= 2 * k; ++i) {         dd[i] += dd[i - 1];         res = min(res, n - dd[i] - cnt[i]);       }       cout << res <<   n ;     }   }   