要仔细找一下矩阵的规律，用min( , )求较小值

#include<iostream>
using namespace std;
int main()
{
    int n;
    while(cin>>n,n)
    {
        for(int i=1;i<=n;i++)
        {
            for(int j=1;j<=n;j++)
            {
                int up=i,down=n-i+1,left=j,right=n-j+1;
                cout<<min(min(up,down),min(left,right))<<' ';
            }
            cout<<endl;
        }
        cout<<endl;
    }
    return 0;
}