Ring wise Matrix Rotation

Introduction Matrices have always been of interest in the field of encryption, specifically matrix rotations which leads to a symmetric as well as asymmetric cryptography. To learn more about regular matrix rotation please check my recent posts on the subject. This however is a fancy Ring wise Matrix Rotation and is no where related to the regular rotation of matrices. Problem Statement You are given a M*N grid with the restriction that the minimum of M and N is an even number. Rotate each of the rings by a distance K. We can choose the direction of rotation to be either clockwise or anti-c...

Closest Pair Points

Introduction A very interesting problem, indeed. I presume, not a complex one either. Here is what the problem statement looks like. "Given a set of N points in a plane, find the closest pair points". A question which is always asked in interviews in various forms, here we will not just look at the solution but will also understand the intuition behind the solution. In the adjoining image, we have five points (A, B, C, D, E) in the plane. As a result of the solution we need to return one pair which has the smallest distance between them. Of course there can be multiple such pairs, we a...

Seed in Random Number Generation

Random Numbers Randomization is an awesome concept. Efficiency of most of the algorithms are proportional to how randomly the algorithm is implemented. Talking about one the best sort algorithms - Quick Sort. The efficiency depends on the choice of pivot and it is wise to choose a pivot randomly to get an even distribution of elements around it. Of course no one can beat my bad luck if my randomly chosen pivot misbehaves. But still you will be luckier and have a better running time and upper bound on the running time of this algorithm. This is not the only algorithm where randomization ...