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I like puzzles like this, where it's not just "what does each person know?" but also "when did they know it?" Another similar puzzle, with more logic and fewer
by kej 4y ago
I like puzzles like this, where it's not just "what does each person know?" but also "when did they know it?"
Another similar puzzle, with more logic and fewer numbers, is this one which was nicely written up on xkcd: https://xkcd.com/blue_eyes.html https://xkcd.com/blue_eyes.html
- xdfgh1112 4y agoBilled as "the hardest logic puzzle in the world". Now I feel less dumb for not solving it myself when it appeared in Cracking the Code Interview.
- lmm 4y agoI guess that's the root for https://slatestarcodex.com/2015/10/15/it-was-you-who-made-my-blue-eyes-blue/ https://slatestarcodex.com/2015/10/15/it-was-you-who-made-my... .
- thaumasiotes 4y ago> this one which was nicely written up on xkcd But there's not a writeup there. That's just a statement of the problem. This is not the hardest logic puzzle in the world, though stating the answer can be tricky. If it takes one day for a solitary blue-eyed person to realize he's the one with blue eyes and leave, then it takes 100 days for a group of 100 blue-eyed people to realize they have blue eyes and leave. The blue eyes puzzle relies on everyone receiving input from the same synchronized digital clock ("Every night at midnight, a ferry stops at the island"), which is unusual for a logic puzzle. The puzzle here is similarly discretized, but it's more a pure question of sequence - each line of dialog happens after the previous line, and that's all that matters.
- xdfgh1112 4y agohttps://xkcd.com/solution.html https://xkcd.com/solution.html
- deleted 4y ago[deleted]
- conradludgate 4y agoThat was a good puzzle. I won't put the answer here for spoilers, but there is a neat solution. If you get stuck, try imagine a different number of blue/brown eyes on the island and what that might change