input() vs sys.stdin Showdown
Why plain input() costs you on big tests.
The Hidden Cost of input()
Every input() call does extra work behind the scenes. On a few lines that is fine, but contests can throw thousands of lines at you. ⏱️
Why It Adds Up
The slowdown is the per-call overhead: prompts, flushing, and encoding checks repeat on every single line you read.
All lessons in this course
- input() vs sys.stdin Showdown
- Parse Many Numbers on One Line
- Batch Output the Right Way
- Read N Lines and Edge Cases