Hash collisions explained with a tiny phone book
Trace separate chaining in a five-bucket phone book, distinguish a hash collision from a duplicate key, and explain the assumptions behind expected constant time.
Foundation
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A little theory. A lot of practice.
Use primary keys and foreign keys to preserve an order
Model order identity, reject orphan references, inspect cascades and separate database relationships from the policy for deleting a paid order.
Foundation
Read and replace a bit field without losing nearby bits
Replace a three-bit field in an eight-bit word, verify unaffected bits, and see why device registers need a separate access contract.
Foundation
Use a table when readers compare values
Mark row and column headers in a plan comparison, preserve units and accessible names, and keep wide tables usable on narrow screens.
Foundation
Big O with a contact-list search you can count
Count the comparisons in a contact search, then see what changes when the list is sorted or indexed. A practical introduction to Big O with JavaScript.
Foundation