Codeforces Round #719 (Div. 3)C. Not Adjacent Matrix
给数字n, 求一个n x n的矩阵, 每两个相邻个子的大小之差不能是1.
先放单数1 3 5 7, 再放2 4 6 8 即可.
#include "bits/stdc++.h"
using namespace std;
// fast read
const auto fr = [](){
std::ios_base::sync_with_stdio(0); std::cin.tie(0);
std::cout << std::fixed << std::setprecision(12);
return 1;
}();
template<typename A> ostream& operator<<(ostream &cout, vector<A> const &v);
template<typename A, typename B> ostream& operator<<(ostream &cout, pair<A, B> const &p) { return cout << "(" << p.first << ", " << p.second << ")"; };
template<typename A> ostream& operator<<(ostream &cout, vector<A> const &v) {
cout << "["; for(int i = 0; i < v.size(); i++) {if (i) cout << ", "; cout << v[i];} return cout << "]";
}
template<typename A, typename B> istream& operator>>(istream& cin, pair<A, B> &p) {
cin >> p.first;
return cin >> p.second;
}
// vars:
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vi = std::vector<int>;
using vl = std::vector<ll>;
using vvi = std::vector<vi>;
using vvl = std::vector<vl>;
using pii = std::pair<int,int>;
using pil = std::pair<int,ll>;
using pli = std::pair<ll,int>;
using pll = std::pair<ll,ll>;
using vpii = std::vector<pii>;
using vvpii = std::vector<vpii>;
// consts
ll M = 0;
// ksm (kuai su mi)
ll ksm(ll a,ll p){ll res=1;while(p){if(p&1){res=res*a%M;}a=a*a%M;p>>=1;}return res;}
int main() {
fr;
int T;
cin >> T;
while (T--)
{
int N;
cin >> N;
if(N == 1)
{
cout << 1 << endl;
continue;
}
if(N == 2)
{
cout << -1 << endl;
continue;
}
int count = 1;
for (int i = 1; i <= N * N ; i+=2)
{
cout << i << " ";
if((count ) % N == 0)
{
cout << "\n";
}
count++;
}
for (int i = 2; i <= N * N ; i+=2)
{
cout << i << " ";
if((count ) % N == 0)
{
cout << "\n";
}
count++;
}
}
return 0;
}