Space-time tradeoff Emoji Note

Anthony has shared wonderful tips on interviewing at Google.

Interviewing at Google? Here’s 6 Things You Absolutely Need To Do
Anthony D. Mays


Within the fourth tip, Brainstorm solutions and their time/space complexity, Anthony stressed on “space-time tradeoff principle", which I was vaguely familiar with.
While attempting to understand it, I drew a sketchnote.

As it’s not sharable, I came up with emoji version.

Space-time Tradeoff Table

(faster + more space)
(slower + less space)

(Lookup table)


πŸ’Ύ x 1
(Uncompressed Data)

πŸ’Ύ x 0.5
(Compressed Data)

(Stored Image)


(Loop Unrolling)

πŸ‘¨β€πŸ’» x 0.5
(Smaller code)

Gist of each tradeoff

πŸ™„πŸ“‘(Lookup table) vs. πŸ”ƒπŸ’» (Recalculation)
Saving computed data in memory saves time but increases the space usage.
πŸ’Ύ x 1 (Uncompressed Data) vs. πŸ’Ύ x 0.5 (Compressed Data)
Faster to access uncompressed data as no decompression step is needed but requires more space.
πŸͺπŸ–Ό (Stored Image) vs. πŸ”ƒπŸ“œ (Re-render)
Storing image in cache is faster than re-rendering but requires more space (in disk/memory).
➿➑➰ (Loop Unrolling) vs. πŸ‘¨β€πŸ’» x 0.5 (Smaller code)
Loop unrolling can optimize execution speed at the cost of increased binary size.

It might be a bit too much of emojis but helped me to understand a bit better what tradeoffs are available.
Feel free to share your version of table or sketchnote πŸ™‚