battleship revisited
Source: XI May Olympiad (Olimpiada de Mayo) 2005 L2 P5
September 19, 2022
combinatoricscombinatorial geometry
Problem Statement
The enemy ship has landed on a board that covers exactly squares of the board, like this:
https://cdn.artofproblemsolving.com/attachments/2/4/ae5aa95f5bb5e113fd5e25931a2bf8eb872dbe.png
The ship is invisible. Each defensive missile covers exactly one square, and destroys the ship if it hits one of the squares that it occupies. Determine the minimum number of missiles needed to destroy the enemy ship with certainty .