我的眼里满是RE

#include<bits/stdc++.h>
#define ll long long
using namespace std;
int n,a[30][30],x,y;
int main(){
	cin>>n;
	y=n/2;
	a[x][y]=1;
	for(int i=2;i<=n*n;i++){
		int t1=(x+n-1)%n,t2=(y+1)%n;
		if(a[t1][t2]==0){
			a[t1][t2]=i;
		}else{
			t1=(x+1)%n;
			t2=y;
			a[t1][t2]=i;
		}
		x=t1;
		y=t2;
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			cout<<a[i][j]<<" ";
		}
		cout<<"\n";
	}
	return 0;
}