TOT 242 1989 Autumn A S6 at least 1 star in each column in m x n array
Source:
March 12, 2021
combinatoricstable
Problem Statement
A rectangular array has rows and columns, where . Some cells of the array contain stars, in such a way that there is at least one star in each column. Prove that there is at least one such star such that the row containing it has more stars than the column containing it.(A. Razborov, Moscow)