Problem link: https://mirror.codeforces.com/problemset/problem/2181/B
I'm specifically not able to make sense of this claim
In each pair of moves, at least the maximum is subtracted from the sum of all N numbers. Therefore, the total sum is multiplied by at most $$$1 − \frac{1}{N}$$$ in each step.
I've tried getting AI to explain it to me but it keeps getting confused as well :((
Auto comment: topic has been updated by project2400 (previous revision, new revision, compare).
Auto comment: topic has been updated by project2400 (previous revision, new revision, compare).
Let $$$S$$$ denote the sum of elements in play. The maximum element must be at least $$$\frac{S}{N}$$$. After one turn, the sum goes from $$$S$$$ to ($$$S$$$ minus max element), which is at most $$$S - \frac{S}{N}$$$; that is, S is multiplied by a factor of at most $$$1 - \frac{1}{N}$$$. So the maximum possible number of turns is $$$\log_{(1 - \frac{1}{N})^{-1}} S$$$, which after change of base, yields the subsequent arithmetic.