EPSSSE : Essential Problem-Solving Skills for Software Engineers

      Leetcode - 189 Rotate Array Problem:  https://leetcode.com/problems/rotate-array/ The given problem expects the given array to be rotated to the right by k steps.  For example, given [1, 2, 3, 4, 5, 6] and k = 3, we need to perform the following: and hence we get the array, [4, 5, 6, 1, 2, 3] We can generalize the problem as following: Given an array of n-elements, perform m-rotations by magnitudes r[0], r[1], ...., r[m-1] given as array r, either by left or right given by array d[0], d[1], d[2], ...., d[m-1]. If d[i] = 0, then rotate left or rotate right otherwise. We try solving this version of the problem. Finally we reduce the generalized problem into the original problem. Solution 1: ...

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 Leetcode - 295 Find Median From Data Stream Problem:  https://leetcode.com/problems/find-median-from-data-stream/ For a given stream of integers we need to return the median. Median is the middle value in a sorted integer list with odd number of elements and if the list has even number of elements then median is mean of  two middle values. Solution 1: Brute-force - O(nlogn), O(1) time, O(1) space [TLE] In this method we follow the most trivial method to find the median. We sort the container which stores the input from the stream. From the sorted container find the middle value(s) to find the median. The container can a vector as we can sort it easily, insert at the end in constant time and elements are indexed to find the middle value(s).           vector<int> arr; MedianFinder() { ...