Chef Kao cut a pizza into 2k pieces
Source: 2022 Thailand Online MO P6
April 4, 2022
combinatorics
Problem Statement
Let and be positive integers. Chef Kao cuts a circular pizza through diameters, dividing the pizza into equal pieces. Then, he dresses the pizza with toppings. For each topping, he chooses consecutive pieces of pizza and puts that topping on all of the chosen pieces. Then, for each piece of pizza, Chef Kao counts the number of distinct toppings on it, yielding numbers. Among these numbers, let and being the minimum and maximum, respectively. Prove that .