A data structure is a named location that can be used to store and organize data. And, an algorithm is a collection of steps to solve a particular problem. Learning data structures and algorithms allow us to write efficient and optimized computer programs. Hope you enjoy the journey of learning data structures and algorithms.
Arrays are a simple data structure for storing lots of similar items. They exist in all programming languages, and are used as the basis for most other data structures. On their own, Arrays can be used to solve many interesting problems. Arrays come up very often in interview problems, and so being a guru with them is a must!
Be familiar with the basic operations in a string, especially the unique operations which we don't have in an array Understand the differences between different comparison functions.
Determine whether the string is immutable or not in your favorite language and understand the impact of this feature.
Be able to solve basic string-related problems.
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 7 | Reverse Integer | JavaScript | O(n) | O(1) | Easy |
| 28 | Implement strStr() | JavaScript | O(n^2) | O(1) | Easy |
| 67 | Add Binary | JavaScript | O(n) | O(1) | Easy |
| 14 | Longest Common Prefix | JavaScript | O(n^2) | O(1) | Easy |
| 344 | Reverse String | JavaScript | O(n) | O(1) | Easy |
| 485 | Max Consecutive Ones | JavaScript | O(n) | O(1) | Easy |
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 1025 | Divisor Game | JavaScript | O(1) | O(1) | Easy |
Hash Table is a data structure which organizes data using hash functions in order to support quick insertion and search.
There are two different kinds of hash tables: hash set and hash map.
The hash set is one of the implementations of a set data structure to store no repeated values. The hash map is one of the implementations of a map data structure to store (key, value) pairs. It is easy to use a hash table with the help of standard template libraries. Most common languages such as Java, C++ and Python support both hash set and hash map.In Javascript Map and Set
By choosing a proper hash function, the hash table can achieve wonderful performance in both insertion and search.
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 1 | Two Sum | JavaScript | O(n) | O(1) | Easy |
| 575 | Distribute Candies | JavaScript | O(1) | O(1) | Easy |
| 204 | Count Primes | JavaScript | O(n) | O(1) | Easy |
| 1365 | How Many Numbers Are Smaller Than the Current Number | JavaScript | O(n) | O(1) | Easy |
| 136 | Single Number | JavaScript | O(n) | O(1) | Easy |
What is Binary Search? Binary Search is one of the most fundamental and useful algorithms in Computer Science. It describes the process of searching for a specific value in an ordered collection.
Terminology used in Binary Search:
Target - the value that you are searching for Index - the current location that you are searching Left, Right - the indicies from which we use to maintain our search Space Mid - the index that we use to apply a condition to determine if we should search left or right.
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 704 | Binary Search | JavaScript | O(log(n)) | O(1) | Easy |
| 35 | Search Insert Position | JavaScript | O(log(n)) | O(1) | Easy |
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 1221 | Split a String in Balanced Strings | JavaScript | O(n) | O(1) | Easy |
| 1486 | XOR Operation in an Array | JavaScript | O(1) | O(1) | Easy |
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 70 | Climbing Stairs | JavaScript | O(n) | O(1) | Easy |
Recursion is an important concept in computer science. It is a foundation for many other algorithms and data structures. However, the concept of recursion can be tricky to grasp for many beginners.
| S.No | Title | Solution | Time | Space | Difficulty |
|---|---|---|---|---|---|
| 344 | Reverse String | JavaScript | O(n) | O(1) | Easy |