Optimize Log File

Problem Overview

• Task: choose a subset of swap operations to reorder a permutation of log entries into the lexicographically smallest sequence.
• Input/Output: a permutation entries of length n (distinct 1..n) and n swap ops indexed 0..n−1; each used at most once, any order; 0-based indexing; return the smallest permutation; constraints 1 < n ≤ 2e5.
• Context: optimize a log file arrangement to ease real-world log analysis.
• Company/SEO: From Google interviews; a coding interview problem and interview question.