我需要一种算法，以确定是否一个数组包含两个要素总和到一个给定的整数。

I need an algorithm to determine if an array contains two elements that sum to a given integer.

数组排序。

该算法应该是递归并为O（N）。

The algorithm should be recursive and runs in O(n).

递归步骤应基于总和，这意味着该方法进入的总和，并返回真或假根据最终结果（如果两个元件发现 - 返回true，否则 - 返回false）

The recursive step should be based on the sum, meaning the method passes the sum and return true or false depending on the end result (if two elements are found - return true, else - return false)

仅线性数据结构都可以使用。

Only linear data structures can be used.

任何想法是AP preciated ..

Any ideas are appreciated..

推荐答案

您可以将任何迭代算法为递归其用（例如）的尾递归。我会更广阔，如果不是功课。我想你会明白它的其他职位。

You can convert any iterative algorithm into a recursive one by using (for instance) tail recursion. I'd be more expansive, if it weren't homework. I think you'll understand it from the other post.