why 全WA？？（悬关求调）

#include<bits/stdc++.h>
using namespace std;
const int N=10;
int n,a[N][N],to[5][2*N],c=0;
bool canAttack(int x,int y){
	return to[1][x]==1||to[2][y]||to[3][x-y+n]==1||to[4][x+y-1]==1;
}
void print(){
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cout<<a[i][j]<<" ";
		}
		cout<<endl;
	}
	cout<<endl<<c;
}
void search(int t){
	if(t>n){
		print();
		return;
	}
	for(int i=1;i<=n;i++){
		if(canAttack(t,i)) continue;
		a[t][i]=t;
		to[1][t]=1;
		to[2][i]=1;
		to[3][t-i+n]=1;
		to[4][t+i-1]=1;
		c++;
		search(t+1);
		a[t][i]=0;
		to[1][t]=0;
		to[2][i]=0;
		to[3][t-i+n]=0;
		to[4][t+i-1]=0;
		c--;
	}
}
int main(){
    cin>>n;
	search(1);
	return 0;
}