Week 7 was hash maps and two pointers — patterns that lean on Python's built-in dict, set, and list.
Week 8 was different. This week I built the data structures themselves. Stacks, queues, linked lists — implementing them from scratch before using them to solve real problems. By the end of the week I had a browser history tracker with working back and forward buttons, built on the same logic LeetCode problems made me practice all week.
Month 2 is done. Here's how it closed out.
Day 50 — Stacks: LIFO, From Scratch
A stack is the simplest data structure with a personality: last in, first out. Whatever you added most recently is the first thing you remove. Think of a stack of plates — you take from the top.
