Any two pupils in the school are either friends or not, the friendship is mutual. For each
integer 1 ≤ ℓ ≤ 111 there is a school pupil having exactly ℓ friends in the school. Given that
there is no triple of school pupils such that any two of them are friends, find the minimal
possible number of pupils in this school.
Correct Solutions by,
- Toshihiro Shimizu Kawasaki, Japan
- Choi Min Kyu South Korea
- Mustafa Kerem Yüksel Bilkent University
- Vedat deveci İstanbul
- Hüseyin Ege Olcay Bilkent University
- Alper Balcı Ohio State University, USA
- Henrik Aberg Gothenburg, Sweden
- Jakob Aberg Lund, Sweden
- Kürşad Mestav New Jersey, USA
- Abdulkadir Tanrıverdi Eskişehir
- Magnus Jakobsson, Lund, Sweden
- Roger Bengtsson, Lund, Sweden
- Mustafa Burak Topal İstanbul
- Cenk Bağrıyanık NFA, New York, USA
Solution: http://www.fen.bilkent.edu.tr/~cvmath/Problem/2303a.pdf