Leetcode 2563. Count the Number of Fair Pairs | Two Pointers | Leetcode 2563 Explained in Python

In this video, we solve Leetcode 2563: Count the Number of Fair Pairs using the efficient Two Pointers technique.
A fair pair is defined as a pair of indices (i, j) where i less than j and the sum of nums[i] + nums[j] lies within a given [lower, upper] range.

We go through:
Brute force approach & its limitations
Sorted array + Two Pointers strategy
Why find(upper) - find(lower - 1) works
Dry run with example
Time complexity analysis
Ideal for coding interviews and learning range-based logic with arrays.

🧠 Topics Covered:

Two Pointers
Sorting
Pair Sum Problems
Range Conditions on Arrays
Efficient Counting
Python Coding Patterns

🔍 Tags
Leetcode 2563, Count Fair Pairs, Two Pointers Leetcode, Leetcode Python tutorial, Pair sum problems, Sorted array technique, Fair pair count, Range-based array problems, Count number of fair pairs, DSA with Python, Coding interview practice, Efficient two pointers, Leetcode solution explained, Leetcode sorting problems, Python two pointer tutorial, Subarray problems Leetcode, Count index pairs, Python DSA tips, Pair sum range

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