Smashed the rest of the Sliding Window pattern! Minimum Window Substring was a tough Hard problem, but the key insight of storing indices instead of slicing substrings every time saved significant overhead.
Learned to optimize character frequency maps (reducing time from O(26*n) to O(n)).
Tackled the gaming distraction from yesterday with a strict, non-negotiable hard stop today. Back on track.
Next Day Goal
Tackle the backlog notes for LinkedList cycle detection.
Start the next DSA pattern (e.g., Two Pointers / Heap or review Tree DFS/BFS).