100 & 101 moves for a knight to reach squares in chessboard
Source: XVIII Tuymaada Mathematical Olympiad (2011), Senior Level
July 29, 2011
combinatorics unsolvedcombinatorics
Problem Statement
Written in each square of an infinite chessboard is the minimum number of moves needed for a knight to reach that square from a given square . A square is called singular if is written in it and is written in all four squares sharing a side with it. How many singular squares are there?