求助巨佬，为何#2WA掉了

#include<bits/stdc++.h>
using namespace std;
int a[39][39];
int n;
int main(){
	cin>>n;
	memset(a,0,sizeof(a));
	int x=1,y=(n+1)/2;
	a[x][y]=1;
	for(int k=2;k<=n*n;k++){
		if(x==1&&y!=n){
			x=n;
			y=y+1;
			a[x][y]=k;
		}
		else if(x!=1&&y==n){
			x=x-1;
			y=1;
			a[x][y]=k;
		}
		else if(x==1&&y==n){
			x=x+1;
			y=y;
			a[x][y]=k;
		}
		else if(x!=1&&y!=n){
			if(a[x-1][y+1]==0){
				x=x-1;
				y=y+1;
				a[x][y]=k;
			}
			else{
				x=x+1;
				y=y;
				a[x][y]=k;
			}
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cout<<a[i][j]<<" ";
		}
		cout<<endl;
	}
	return 0;
}

若能全绿，在下蒟蒻必将感恩戴德，鼎力关注