等差数列求和可以推导出 $s$ 数列的所有的值,其中 $s_1 = 3(n + 1)/2$,因此 $n$ 只能是奇数。构造解的思路在上面题解的评论区,先构造出和相等的数对,前 $n$ 个数字正序排列,后 $n$ 个数字倒序排列。设 $s$ 数组正中间的值是 $d$,那么只需要交换一些数字构造出 $d+0, d+1, d-1, d+2, d-2, \dots$,奇数增量嵌套构造即可,偶数同理。
// 2023/11/19
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <algorithm>
#include <utility>
#include <functional>
using namespace std;
const int INF = 0x3f3f3f3f, MOD = 1e9 + 7;
const double eps = 1e-8;
const int dir[8][2] = {
{0, 1}, {0, -1},
{1, 0}, {-1, 0},
{1, 1}, {1, -1},
{-1, 1}, {-1, -1},
};
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> VI;
typedef pair<int, int> PII;
const ull Pr = 131;
#define LN ListNode
#define LNP ListNode*
#define TN TreeNode
#define TNP TreeNode*
#define For(i, a, b) for (int i = int(a); i < int(b); ++i)
#define Rof(i, a, b) for (int i = int(b) - 1; i >= int(a); --i)
#define For1(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define Rof1(i, a, b) for (int i = int(b); i >= int(a); --i)
#define ForE(i, j) for (int i = h[j]; i != -1; i = ne[i])
#define f1 first
#define f2 second
#define pb push_back
#define has(a, x) (a.find(x) != a.end())
#define nonempty(a) (!a.empty())
#define all(a) (a).begin(),(a).end()
#define SZ(a) int((a).size())
#ifdef DEBUG
#define debug1(x) cout << #x" = " << x << endl;
#define debug2(x,y) cout << #x" = " << x << " "#y" = " << y << endl;
#define debug3(x,y,z) cout << #x" = " << x << " "#y" = " << y << " "#z" = " << z << endl;
#else
#define debug1
#define debug2
#define debug3
#endif
#ifdef DEBUG
struct ListNode {
int val;
ListNode *next;
ListNode() : val(0), next(nullptr) {}
ListNode(int val) : val(val), next(nullptr) {}
ListNode(int val, ListNode *next) : val(val), next(next) {}
};
struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode() : val(0), left(nullptr), right(nullptr) {}
TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
};
#endif
const int N = 200010;
int t, n;
PII a[N];
int main(int argc, const char * argv[]) {
#ifdef USE_INPUT_FILE
freopen("input.txt", "r", stdin);
#endif
std::ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
cin >> t;
while (t--) {
cin >> n;
if (n % 2 == 0) {
cout << "NO\n";
continue;
}
if (n == 1) {
cout << "YES\n1 2\n";
continue;
}
For1(i, 1, n) {
a[i].f1 = 2 * n + 1 - i;
a[i].f2 = i;
}
int top = (n - 1) / 2;
int l = 1, r = 1 + top;
while (l < r) {
swap(a[l].f2, a[r].f2);
l++; r--;
}
l = top + 2, r = n;
while (l < r) {
swap(a[l].f2, a[r].f2);
l++; r--;
}
cout << "YES\n";
For1(i, 1, n) {
cout << a[i].f1 << ' ' << a[i].f2 << '\n';
}
}
return 0;
}