When should I use Basics of Strings?

Basic text processing. Checking for palindromes.

Is Basics of Strings asked in FAANG interviews?

Yes, Basics of Strings is commonly tested in FAANG and top tech company interviews.

Basics of Strings

Q: What is the time complexity of Basics of Strings?

Best: varies, Average: O(N), Worst: varies. Space: varies.

Understand String representation (ASCII) and basic operations like Reversal.

Input String

Ready to reverse string.

H

e

101

l

108

l

108

o

111

Intuition

Strings are sequences of characters. In many languages, they are immutable (cannot be changed in place). Reversing a string typically involves swapping characters from both ends moving towards the center.

Concept

ASCII: Each character is stored as a number (e.g., 'A' = 65, 'a' = 97).
Immutability: In Java/Python, strings are immutable. Modifying them creates a new string. In C++, they are mutable.
Reversal: Use two pointers (start and end) and swap until they meet.

How it Works

Reversal Algorithm:

Initialize L = 0, R = n - 1.
While L < R:
Swap str[L] and str[R].
L++, R--.

Step-by-Step Breakdown

Watch the visualization:

See the ASCII values for each character.
Watch the characters swap positions during reversal.

When to Use

Basic text processing.
Checking for palindromes.

When NOT to Use

N/A (Fundamental concept).

How to Identify

"Reverse string", "ASCII value", "Character manipulation".

Sample Problems

Reverse String

Write a function that reverses a string. The input string is given as an array of characters.

Boyer-Moore Voting

Palindrome Check

Frequently Asked Questions

What is Basics of Strings?