Find Maximum Packages

Problem Overview

• Given item costs, find the maximum number of packages where each package has at most 2 items and all packages share the same total cost; each item can be used once.
• Input: int array cost of size n; Output: int maximum number of such packages.
• Constraints: 1 ≤ n ≤ 2×10^5, 1 ≤ cost[i] ≤ 2000.
• Real-world context: Amazon marketplace inventory bundling to enhance sales.
• From Amazon interviews; a coding interview problem and interview question.