m*******r
发帖数: 4468 | 1 看到一个trader的 phone interview， 两道题不是很明白。
my roommate and I are having a house party. We invite 15 couples. At the
party, everyone must shake hands with everyone whom they do not already
know. At the end of the party, I can't remember the number of people I
have met, so I go ask all other people at the party how many hands they
have shaken, and they each tell me a different number. You do not shake
hands with yourself or your 'partner' (the person with whom you came). How
many hands did my roommate shake?
I'm thinking of a 10-digit number, where each digit represents the number
of that ordinal number in the whole number. So, the first digit represents
the number of 0's in the whole 10 digits. The second digit represents the
number of 1's in the whole 10 digits. And so on. The first digit is not a
'0.' What is my number. |
|
