When does a doubling array pay a big copy?

• On every append
• When items are read
• Only when the array fills

What does an amortised bound describe?

• One lucky input
• The average over any sequence
• The cost of one line of code

An amortised bound is an average-case claim about random inputs.

Circle one:   True   False

A resize copies 8 items. What pays for it?

• The stored credits on those slots
• A faster processor
• Deleting other arrays

Each cheap append stores 2 credits. After 4 such appends, type the stored credits.

Answer: ______________

Why does a million appends cost a few million steps, not a million squared?

• Copies thin out as the array grows
• Appends skip writing entirely
• Squares round down at scale

With three coins per append, a hostile sequence can still break the constant average.

Circle one:   True   False

A critic points at one copying append and calls the structure linear per append. What is the flaw?

• Copying appends never occur
• One costly call cannot price a whole run
• Arrays forbid all analysis