3 ms·
Another way to think about it: forget about how many people there are in total, I can observe x blue eyes. Let m be the minimum globally known number of people
by greendestiny 19y ago
Another way to think about it: forget about how many people there are in total, I can observe x blue eyes. Let m be the minimum globally known number of people with blue eyes. After the announcement m = 1.
On that day (and any subsequent) if your x < m you know you have blue eyes. If at the end of the day noone leaves, m must be at least m + 1.
- eru 19y agoSpoiler: Knowing Mathematical induction (http://en.wikipedia.org/wiki/Mathematical_induction http://en.wikipedia.org/wiki/Mathematical_induction) really helps. It was not that hard at all.
- eru 19y agoTo correct myself: It was a little bit harder than it seemed at first. I forgot to prove that my solution was optimal.