Difference between revisions of "2015 OIM Problems/Problem 6"

(Created page with "== Problem == Beto plays the following game with his computer: initially his computer randomly chooses 30 numbers from 1 to 2015, and Beto writes them on a blackboard (there m...")
 
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
 
== Problem ==
 
== Problem ==
Beto plays the following game with his computer: initially his computer randomly chooses 30 numbers from 1 to 2015, and Beto writes them on a blackboard (there may be numbers repeated); At each step, Bob chooses a positive integer <math>k</math> and some of the numbers written in the blackboard, and subtracts the number <math>k</math> from each of them, with the condition that the numbers resulting results remain non-negative. The objective of the game is to achieve that at some point all 30 resulting numbers equal 0, in which case the game ends. Find the smallest number <math>n</math> such that, regardless of the numbers he initially chose the computer from him, Beto can finish the game in at most <math>n</math> steps.
+
Beto plays the following game with his computer: initially his computer randomly chooses 30 numbers from 1 to 2015, and Beto writes them on a blackboard (there may be numbers repeated); At each step, Beto chooses a positive integer <math>k</math> and some of the numbers written in the blackboard, and subtracts the number <math>k</math> from each of them, with the condition that the numbers resulting results remain non-negative. The objective of the game is to achieve that at some point all 30 resulting numbers equal 0, in which case the game ends. Find the smallest number <math>n</math> such that, regardless of the numbers he initially chose the computer from him, Beto can finish the game in at most <math>n</math> steps.
  
 
~translated into English by Tomas Diaz. ~orders@tomasdiaz.com
 
~translated into English by Tomas Diaz. ~orders@tomasdiaz.com
Line 8: Line 8:
  
 
== See also ==
 
== See also ==
 +
[[OIM Problems and Solutions]]

Latest revision as of 14:06, 14 December 2023

Problem

Beto plays the following game with his computer: initially his computer randomly chooses 30 numbers from 1 to 2015, and Beto writes them on a blackboard (there may be numbers repeated); At each step, Beto chooses a positive integer $k$ and some of the numbers written in the blackboard, and subtracts the number $k$ from each of them, with the condition that the numbers resulting results remain non-negative. The objective of the game is to achieve that at some point all 30 resulting numbers equal 0, in which case the game ends. Find the smallest number $n$ such that, regardless of the numbers he initially chose the computer from him, Beto can finish the game in at most $n$ steps.

~translated into English by Tomas Diaz. ~orders@tomasdiaz.com

Solution

This problem needs a solution. If you have a solution for it, please help us out by adding it.

See also

OIM Problems and Solutions