We have three lists which contain people's names.
All three lists have been sorted alphabetically.
Now we need to find at least one name which appear in all three lists.
我想的算法是这样的:
I get three heads out of three lists.
if the three heads are not equal to each other, then I keep the max one and get two new heads from the lists from which I just dropped the heads.
Continue above procedure until I find such an element as described in the beginning.
这个算法正确吗？
问题是我不确定如何使用ocaml来编写函数。
最佳答案
这是一个 OCaml 函数，它使用您的算法对两个排序列表进行交集(这确实是解决此问题的好方法)。
let rec intersect l1 l2 = match l1, l2 with
| [], _ | _, [] -> []
| h1 :: t1, h2 :: t2 ->
if h1 < h2 then intersect t1 l2
else if h1 = h2 then h1 :: (intersect t1 t2)
else intersect l1 t2
关于algorithm - 在 OCaml 的所有三个列表中找到至少一个存在的元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14385190/