Another Ah moment
Posted: Wed Apr 12, 2017 1:29 am
You are given a TV screen with $n×(n+2)$ pixels(the dimension is $n $ on a side and $n+2$ on another side).
Initially, there are $k $ pixels turned on. In any $2×2$ screen, as soon as there are $3$ unit screens which are off, you can turn off the $4$th screen. Your goal is to turn the whole TV off. Find the least $k $ such that you fail for every configuration.
Initially, there are $k $ pixels turned on. In any $2×2$ screen, as soon as there are $3$ unit screens which are off, you can turn off the $4$th screen. Your goal is to turn the whole TV off. Find the least $k $ such that you fail for every configuration.