Lists (1D and 2D)

In this module

Build and grow a list with a literal, .append(), and a list comprehension.
Summarize a list with sum(), sorted(), reversed(), any() and all(), and pair values with enumerate() and zip().
Build a 2D grid of lists, and avoid the [[0] * m] * n aliasing bug that shares one row across every entry.
Recognize which list operations cost more as a list grows, and allocate n + 1 slots for a 1-indexed problem.

Try these on the judges. Each link opens the problem on WMOJ or DMOJ.

2026 J2
Olympic Scores (opens on WMOJ in a new tab) WMOJ
Drop an athlete's highest and lowest judge scores, then scale what remains by a difficulty factor.
2023 J3
Special Event (opens on WMOJ in a new tab) WMOJ
Find which day of the week has the most people available from a list of weekly schedules.
2016 J2
Magic Squares (opens on DMOJ in a new tab) DMOJ
Check whether every row and column of a grid sums to the same value.
Why DMOJ: Tries the same kind of problem on DMOJ, which holds 2014 to 2020.