2 questions were asked:

• There are n houses in a society, with each containing some value. A thief should steal the maximum he can. He cannot steal from any two adjacent houses because the society has an alarming system. Find the maximum value he can steal. (Initially solved using DP, but the interviewer asked to reduce space complexity).

• There is an enumerated complete binary tree (i.e., elements are 1, 2, 3...). Given an element (key), find whether it is present or not in the tree. (Initially solved by traversing and searching the tree, which is O(n), and the interviewer asked to reduce the time complexity).

Design a system for a mall.