Скачать или смотреть LeetCode 125 — Valid Palindrome | Java Solution & Explanation

Problem: Given a string, determine if it is a palindrome considering only alphanumeric characters and ignoring cases.
Example: "A man, a plan, a canal: Panama" - true, "race a car" - false.

What this video covers

Clear problem statement and constraints.

Intuitive two-pointer approach: advance left/right pointers, skip non-alphanumeric characters, compare characters case-insensitively.

Step-by-step walkthrough of a clean Java implementation.

Handling edge cases (empty string, only non-alphanumeric characters).

Time and space complexity analysis.

Tips for interview-style explanations and common pitfalls.

Complexity

Time: O(n) — single pass with two pointers.

Space: O(1) — constant extra space.

What you'll get

A working Java solution with explanation you can reproduce in interviews.

Best practices for writing readable, bug-resistant code for string manipulation problems.

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