不难也不简单

#include<bits/stdc++.h>
using namespace std;
int n,a[101][101]={0},x=1,y=0,cnt=1;
int main(){
    cin >>n;
    while(cnt <=n*n){
        while(y+1<=n&& a[x][y+1]==0){
            a[x][++y]=cnt++;
        }
        while(x+1<=n&& a[x+1][y]==0){
            a[++x][y]=cnt++;
        }
        while(y-1>=1&& a[x][y-1]==0){
            a[x][--y]=cnt++;
        }
        while(x-1>=1&& a[x-1][y]==0){
            a[--x][y]=cnt++;
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            cout <<a[i][j]<<" ";
        }
        cout<<endl;
    }
}