There are 300 children in a camp. Everyone has no more than $k-1$ friends. What is the smallest $k{}$ for which it might be impossible to create some new friendships so that everyone has exactly $k{}$ friends?
Source: Russian TST 2018, Day 9 P3 (Groups A & B)
Tags: combinatorics, graph theory
There are 300 children in a camp. Everyone has no more than $k-1$ friends. What is the smallest $k{}$ for which it might be impossible to create some new friendships so that everyone has exactly $k{}$ friends?