Amortized time
The average cost per operation over a long sequence, when most operations are cheap and a few are expensive.
Definition
Some operations are usually fast but occasionally slow, like appending to a dynamic array that sometimes has to grow and copy everything. Amortized analysis spreads the rare expensive work over all the cheap operations. Because arrays double their capacity, n appends cost O(n) in total, so each one is O(1) amortized, even though a single append can be O(n).
In practice
Appending to a Swift Array, a Kotlin MutableList or a Java ArrayList is O(1) amortized.
Learn it in context
Lessons that use this term.