Rows in an Array
Source: ToT - 2001 Fall Junior A-Level #3
August 17, 2011
graph theorycombinatorics unsolvedcombinatorics
Problem Statement
Let be an integer. Each row in an array consists of the numbers 1,2,..., in some order, and the numbers in each column are all different. Prove that this array can be expanded into an array such that each row and each column consists of the numbers 1,2,...,.