有没有另一种更短的方法来写下这段代码？（攻击和被攻击函数）

Question

有没有其他方法可以用更短的方式写下这段代码？ OCAML，不是 Objective CAML。

let board = [|('a', 1); ('b', 2); ('c', 3); ('d', 4);('e', 5); ('f', 6); 
              ('g', 7); ('h', 8)|];;

let int_of_col letter = int_of_char letter-96;;

let abs x = if x < 0 then - x else x;;

let attack (a,x)(b,y) = ((int_of_col a - int_of_col b)*(x-y)) 
           = 0 || (abs(int_of_col a - int_of_col b) = abs(x-y));;

let attacked listing = 
    let out = Array.make 8 false in
    for i=0 to 7 do
        for j=0 to 7 do
            if(i != j) then
                if(attack listing.(i) listing.(j)) then out.(i) <- true
                done
            done;
        out;;

Answer 1

abs 存在于 ocaml 中，无需重新实现它。 attacked可以简化为：

let attacked listing =                                                          
  Array.map (fun i -> Array.exists (fun j -> i != j && attack i j) listing) listing

有没有另一种更短的方法来写下这段代码？（攻击和被攻击函数）

Is there another, a bit shorter way to write this chunk of code down? (attack and attacked function)

ocaml

n-queens

有没有另一种更短的方法来写下这段代码？ （攻击和被攻击函数）

Is there another, a bit shorter way to write this chunk of code down? (attack and attacked function)

ocaml

n-queens

有没有另一种更短的方法来写下这段代码？（攻击和被攻击函数）