Need Help with a problem ( Would really appreciate if you guys do the extracredit too) -

4.(Individual, 25 points) Let A be an array containing n distinct integers in increasing order. Given a target value t, you wish to find two integers in A that sum to t, if such a pair exists. Describe a recursive algorithm to solve this problem and determine its asymptotic running time. Extra credit (5 points): Your algorithm is O(n)