Implement String Interning Pool to Reduce Memory

One Copy Per Distinct String

Compilers, JVMs, and Python intern identifiers and literal strings so equality checks become pointer compares. Parsing millions of JSON keys benefits when the same field name like status appears on every row.

Intern Pool Design

Hash table maps string content to canonical storage. On insert, return existing pointer if hash and bytes match.

cCopy
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• Store length with hash to avoid strcmp on collision
• Immutable canonical strings enable pointer equality
• Lifetimes are usually process-long; plan teardown carefully
• Measure memory before/after on duplicate-heavy input

Working Through the Exercise

Keep the relevant documentation open while you implement. When your output disagrees with the reference, trace one failing case by hand before changing random lines.

• Trace first: walk one failing input step by step
• Read the manual: skim the official doc for the mechanism named in this task
• Compare baselines: save measurements from the prior step so speedups are honest

Why for this exercise

You will implement a string intern table and show reduced memory on repetitive input. This exercise asks you to verify that equal strings share one address.