//1.八皇后問題


#include<stdio.h>
#define n 8          
int m=1,a[n];
int ok(int i,int j)           //此函數測試其位置是不是合適
{
   
	int t,b,ok1;
   t=j;b=i;ok1=1;
   while((t>1)&&ok1)              //檢查行是否合適
         {t--;ok1=a[t]!=i; }
   t=j;b=i;
   while((t>1)&&(b>1)&&ok1)             //檢查一個對角線是否合適
         {t--;b--;ok1=a[t]!=b;}
   t=j;b=i;
   while((t>1)&&(b<n)&&ok1)        //檢查另一個對角線是不是合適

         {t--;b++;ok1=a[t]!=b;}
   return ok1;

}
  unknown2(int j)
{
	int i;
	
	if (j>n) {m++;printf("m=%d",m-1); 
    for (i=1;i<=n;i++)   
             {printf("  %d",a[i]);  }  
	  printf("\n ");        }
   else for(i=1;i<=n;i++)
		if(ok(i,j)){a[j]=i;unknown2(j+1);}  
    return m;
}
main()
{
     
	unknown2(1);
	 

     printf("NUMBER=%d \n",  m-1  ); 
	 return 1;
}