Problem solutions from various judges, including DMOJ, SPOJ, WCIPEG, as well as competitions, including the APIO, ACM-ICPC, Bubble Cup, CCC, CCO, COCI, DMOPC, DWITE, Facebook Hacker Cup, IOI, JOI, LKP, and TLE.

Solutions are written in C, C++, Python, Turing, or Haskell.