# LeetCode

Algorithms, Data Structures, Competitive Coding, and problems from LeetCode with complete Solution Approach, Pseudocode, and Explanation.

## Even Odd Separation O(N) Single Iteration

Given an array containing a mix of even and odd numbers, and we need to perform Even Odd Separation. In this post we’ll see how to separate even and odd…

## Tree Traversals – Preorder, Inorder, Postorder

Tree Traversal: visiting every node of a tree. Unlike other linear data structures, where we traverse through every element in order, it’s not the same with the tree. Trees being…

## Program to Evaluate Postfix Expression – LeetCode

Given, an arithmetic expression. We need to Evaluate Postfix Expression, also known as Reverse Polish Notation. Operators include /,*,+,- and we will always return a finite result, there won’t be…

## Balanced Parenthesis Program

We have an expression that contains brackets and alphanumeric characters, and we need to check whether the parenthesis are balanced or not. Balanced Parenthesis means an equal number of opening…

## How the bits/stdc++ .h works in C++

I often wonder, How does #include < bits/stdc++.h> work?. I’ve seen this while solving competitive problems and referring to various solutions and I wanted to know what’s happening in the…

## Separate 0s and 1s – O(N) Single Iteration

Given an array of numbers consisting of only zeroes and ones, and we need to separate 0s and 1s. This problem can be solved in many ways like sorting and…