1 module Main (main) -- q
5 f_queens a_n=f_queens' (enumFromTo (1 :: Int) a_n) a_n;
6 f_queens' a_positions 0=(:) [] [];
7 f_queens' a_positions a_n=c_concat (f_map (f_place (f_queens' a_positions (((-) :: (Int -> Int -> Int)) a_n (1 :: Int)))) a_positions);
8 f_place a_boards a_q=[(:) a_q a_bs|a_bs<-a_boards,f_safe (1 :: Int) a_q a_bs];
9 f_safe a_d a_q []=True;
10 f_safe a_d a_q (a_h:a_t)=
11 if (((==) :: (Int -> Int -> Bool)) a_q a_h)
14 if (((==) :: (Int -> Int -> Bool)) (f_absi (((-) :: (Int -> Int -> Int)) a_q a_h)) a_d)
17 (f_safe (((+) :: (Int -> Int -> Int)) a_d (1 :: Int)) a_q a_t);
19 if (((<) :: (Int -> Int -> Bool)) a_n (0 :: Int))
20 then (((negate) :: (Int -> Int)) a_n)
23 f_main a_n=(++) (show (length (f_queens a_n))) "\n";
25 c_concat=f_foldr (++) [];
26 f_foldr a_op a_r []=a_r;
27 f_foldr a_op a_r (a_a:a_x)=a_op a_a (f_foldr a_op a_r a_x);
28 f_map a_f a_x=[a_f a_a|a_a<-a_x];
29 main = putStr (f_main c_input)