Due to COVID-19, IOI 2021 will be hosted by Singapore online. Visit the official website to learn more.
Coming soon IOI will take place online
The 5th International Olympiad in Informatics was held in Mendoza, Argentina in 1993. You can see four of the problems below, given as separate documents in pdf format for easy reading and printing.
Note that the grading model changed at IOI'94 and beyond.
Before IOI 1994, a human evaluator would sit behind the competitor's computer and do the testing manually (enter test data through the keyboard, check the output on the screen). Starting from IOI 1994, an automatic grading process is used, with test input defined in files.