| “A runaway train is racing toward five men who are tied to the track. Unless the train is stopped, it will inevitably kill all five men. You are standing on a footbridge looking down on the unfolding disaster. However, a fat man, a stranger, is standing next to you: if you push him off the bridge, he will topple onto the line and, although he will die, his chunky body will stop the train, saving five lives. Would you kill the fat man?” |
| “Randomized Algorithms discusses two problems of fine pedigree: counting and generation, both of which are of fundamental importance to discrete mathematics and probability. When asking questions like “How many are there?” and “What does it look like on average?” of families of combinatorial structures, answers are often difficult to find – we can be blocked by seemingly intractable algorithms. Randomized Algorithms shows how to get around the problem of intractability with the Markov chain Monte Carlo method, as well as highlighting the method’s natural limits. It uses the technique of coupling before introducing “path coupling” a new technique which radically simplifies and improves upon previous methods in the area.” |