here are some of my favorite OI problems!

IOI

  • 2020 comparing plants (great writeup by ecnerwala here)
  • 2017 ancient books
  • 2017 simurgh
  • 2015 sorting
  • 2018 seats
  • 2018 highway tolls
  • 2018 werewolf
  • mechanical doll
  • 2020 stations
  • 2016 detecting molecules

JOI

  • Designated Cities
  • Dungeon 3
  • Sandcastle 2
  • JOI Lamps
  • Two Dishes

CF

Simple

These are “simpler” problems that are still quite fun to think about.