Probability Flashcards
Chernoff Bound
The likelihood of being at least some distance away from the middle decreases exponentially on distance
Markov Inequality
The probability something is beyond a bound*expected value must be smaller than 1/bound
Drunkard’s Walk on 2SAT
You can flip bits randomly in a 2SAT solution and mimic drunkards walk - do this 100n^2 times and you have at least a 10% chance of landing past distance n from the origin
Lower and Upper Bound Probabilities for Drunkard’s Walk
If you walked n steps, the probability you’re within 10sqrt(n) from the origin is at least 99%.
If you walked n steps, the probability that you’re at least sqrt(n)/10 steps from the origin is at least 10%
If you walked 100n^2 steps, I can guarantee with at least 99% certainty that you are within 100n steps of the start
If you walked 100n^2 steps, I can guarantee with at least 10% certainty that you are at least n away from the start