2026-06-13

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Daily Prep - Saturday, 2026-06-13

Today’s Targets Completed

DSA - 3 Problems (Striver SDE Sheet Day 13)

• LC1: Rotate List (Medium)
• LC2: Clone List with Random Pointer (Medium)
• LC3: 3Sum (Medium)

System Design - 1 Topic

• Topic: Ticket Master (Revision)

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End Of Day Reflection

• Day 13 of the SDESheetChallenge by takeUforward completed! Smashed 3 core SDE sheet Linked List / Array problems.
• Solved Clone List with Random Pointer (Medium) in-place with $O(1)$ auxiliary space by interleaving duplicate nodes, setting random pointers, and de-interleaving the list.
• Mastered Rotate List (Medium) by forming a circular list and breaking it at the $(N-K(\mathrm{mod}N))$th node, and 3Sum (Medium) using sorting + two-pointer traversal in $O(N^2)$ time.
• System Design: Revised Ticketmaster, reviewing Redis distributed locks for temporary ticket reservations, PostgreSQL unique constraints for absolute double-booking protection, and virtual queues to control massive traffic drops.

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Next Day Goal

• Continue SDE Sheet Hashing / Linked List section.
• System Design: Study tinyurl/bit.ly click analytics pipeline.

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