我需要将列表拆分为所有可能元组的列表,但我不确定如何这样做.
例如:
pairs ["cat","dog","mouse"]
应该导致:
[("cat","dog"), ("cat","mouse"), ("dog","cat"), ("dog","mouse"), ("mouse","cat"), ("mouse","dog")]
我能够形成前两个,但我不确定如何得到其余的.
这是我到目前为止所拥有的:
pairs :: [a] -> [(a,a)]
pairs (x:xs) = [(m,n) | m <- [x], n <- xs]