n*n的棋盘,放n个皇后,互不攻击
一、当n mod 6 != 2 或 n mod 6 != 3时,有一个解为:
2,4,6,8,...,n,1,3,5,7,...,n-1 (n为偶数)
2,4,6,8,...,n-1,1,3,5,7,...,n (n为奇数)
(上面序列第i个数为ai,表示在第i行ai列放一个皇后;... 省略的序列中,相邻两数以2递增。下同)
二、当n mod 6 == 2 或 n mod 6 == 3时,
(当n为偶数,k=n/2;当n为奇数,k=(n-1)/2)
k,k+2,k+4,...,n, 2,4,...,k-2, k+3,k+5,...,n-1, 1,3,5,...,k+1 (k为偶数,n为偶数)
k,k+2,k+4,...,n-1,2,4,...,k-2,k+3,k+5,...,n-2,1,3,5,...,k+1,n (k为偶数,n为奇数)
k,k+2,k+4,...,n-1,1,3,5,...,k-2,k+3,...,n,2,4,...,k+1 (k为奇数,n为偶数)
k,k+2,k+4,...,n-2,1,3,5,...,k-2,k+3,...,n-1,2,4,...,k+1,n (k为奇数,n为奇数)