LeetCode 2006 Count Number of Pairs With Absolute Difference K - From brute force O(n²) to optimal O(n) using frequency array (Easy, Java, O(n))

Jul 12, 2025 · 4 min read · Problem Description LeetCode 2006 Count Number of Pairs With Absolute Difference K Given a 0-indexed integer array nums, return true if it can be made strictly increasing after removing exactly one element, or false otherwise. If the array is already...