Arrays & Strings

Arrays and strings are fundamental data structures used to store collections of elements. They are the building blocks for many algorithms and applications.

Arrays

Arrays store elements sequentially in memory, providing constant-time access to elements by their index. Common operations include:

• Accessing elements: O(1) time complexity
• Searching for an element: O(n) in the worst case
• Insertion/deletion at the end: O(1) amortized time
• Insertion/deletion in the middle: O(n) as elements need to be shifted

Strings

Strings are sequences of characters. In most programming languages, strings are immutable, meaning they can't be modified after creation.

Common string operations include:

• Concatenation: Joining two strings
• Substring: Extracting a portion of a string
• Search: Finding patterns within a string

Common Problems

1. Two Sum
2. Valid Anagram
3. Reverse String
4. Maximum Subarray
5. Longest Palindromic Substring