Almost Hamiltonian path
Source: Ukrainian Mathematical Olympiad 2024. Day 2, Problem 10.8
March 20, 2024
graph theoryHamiltonian pathcombinatorics
Problem Statement
There are cities in a country, some pairs of which are connected by bidirectional flights. For any distinct cities , it is possible to fly directly from some of the cities to some of the cities . Prove that it is possible to plan a route that passes through distinct cities.Proposed by Lior Shayn