# Is Adding a Song Slow? Amortized Cost

One add to a growing playlist just copied 1,024 songs. Work out what adding really costs over a long run of adds, why doubling beats growing a little at a time, and what "amortized O(1)" promises.

![Cheat sheet: Is Adding a Song Slow? Amortized Cost](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/9cf657c9677e482e9ca57a98812dba13.webp)

- Category: Data Structures
- Level: Journeyman
- Tags: Amortized Cost, Constant Time, data structures, Dynamic Array
- Updated: November 3, 2026

Source: https://www.ask-codey.com/cheat-sheets/ds-amortized-cost-cheat-sheet