Leetcode is a primary source to practice for enhancing the problem solving skills. Often the solution that is available is not intuitive enough for a new student to grasp it with clarity. Hence, the steps in this blog are broken down in such a manner that will make students grasp the approach with much more ease. Here, the emphasis is given on various approaches to solve the same problem so that different strategies can be applied to a host of other problems.

Given an array of integers, return the two numbers which add up to a given target. …

Many times, we come across a situation when we have so many variables and it is quite challenging to figure out how to go for selecting the right features for model building. One obvious choice is to use all the variables, however, there are downfalls associated with having all the features, particularly if there is a high-dimensional dataset. The presence of high dimensional dataset gives rise to issues such as increasing computation time, overfitting, poor model accuracy, and high data storage costs. This is known as *curse of dimensionality* problem. There are two key methods of dimensionality reduction.

**Feature selection…**

Vishal Srivastava has a PhD in Engineering and an MBA in Finance. He has interests in making the data science easy for a larger audience.