I had started the #30DaysofCode📚 challenge while I was revising the basic concepts, data structures, and solving easy problems on LeetCode. I documented this so that it helps both me and others to recall what we have learned.

## How to use this list📑

First, look at the given questions, if you are confident with the given concept or feel very familiar, you can skip it else, read the description first and try to solve it. Next, read the solution approach this can help with **Thinking out of the Box** 🧠

The code solutions are written in C++. However, after reading the question and solution approach you will be able to understand the program easily and solve it in your preferred language.

If you find this **#30DaysofCode** list useful, Share it with a friend 💖

## C++ Concepts

## Basics

- Anagram in Strings
- Bubble Sort Algorithm
- Sum of Numbers in a String
- Program to Validate Username
- Perform Set Operations on Arrays
- Maximum Occurring Character in a String

## Medium

- Reverse a Linked List
- Direct & Indirect Recursion
- Balanced Parenthesis Program
- Fibonacci Series – Iterative vs Recursive
- Remove Duplicates from an Unsorted Array
- Remove Duplicates from a Sorted Linked List

## Single Iteration O(N)

- Target Sum – Single Iteration O(N)
- Count the Duplicates of Array O(N)
- Separate 0s and 1s – O(N) Single Iteration
- Even Odd Separation O(N) Single Iteration

## LeetCode

- Two Sum LeetCode Optimized
- Contains Duplicate LeetCode C++
- Single Number in Array LeetCode C++
- Find Missing Number in Array LeetCode
- Squares of a Sorted Array LeetCode O(N)
- Program to Evaluate Postfix Expression – LeetCode

## Data Structures

- Linked List Code in C++
- Stack Program in C++ using Array and STL
- Queue program in C++ using Array and STL
- Tree Traversals – Preorder, Inorder, Postorder

## Searching Algorithms

All the Best!👍 Let’s do this!

### 30DaysofCode

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