BIG-O NOTATION

the seven growth classes: how many steps, how long they take and how far each one lets you go

Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.

Three sizes in one archive — from a sheet on the fridge to a poster on the wall.

Formats: A4 · A3 · A2
What you get: Print-ready PDFs, one per size, with every letterform converted to outlines — nothing to install, nothing to shift.
Subject: code · beginners · reference · study

The model behind every number on this sheet: a step is one elementary operation, the machine performs a billion steps per second, the logarithm is binary and rounded up, and a year is 365.25 days. Constant factors are dropped: they are exactly what O() is silent about, which is why it shows how the cost grows rather than what it is on one particular machine.

HARDWARE MULTIPLIES, THE GROWTH CLASS ONLY ADDS

Put in a machine ten times faster. In class O(n) it really will do ten times more: 1 000 000 000 instead of 100 000 000. In O(n²) only about three times: 100 000 instead of 31 622, a factor of 3.2.

And in O(2ⁿ) it will add 4 elements — from 29 to 33. In O(n!), 1: from 12 to 13. That is why a better algorithm has no substitute in hardware: hardware multiplies, but the growth class only adds.

On the sheet

The model behind every number on this sheet: a step is one elementary operation, the machine performs a billion steps per second, the logarithm is binary and rounded up, and a year is 365.25 days. Constant factors are dropped: they are exactly what O() is silent about, which is why it shows how the cost grows rather than what it is on one particular machine.
Colour carries meaning, but meaning never rests on colour alone — the sheet reads in black and white.
Nothing about how it was made: the sheet carries only what the reader needs.

Printing

Three sizes in the archive: A4 — 210×297 mm, A3 — 297×420 mm, A2 — 420×594 mm.
All text is converted to outlines. No fonts to install, and nothing shifts on another machine.
White background and sparing fills — it prints on a home printer without draining the cartridge.
Margins of at least 10 mm: a home printer cannot print to the edge.
No stroke thinner than 0.3 mm, so nothing disappears in print.

Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 9 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.

BIG-O NOTATION

HARDWARE MULTIPLIES, THE GROWTH CLASS ONLY ADDS

On the sheet

Printing

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