Algebra, Iran MO 2019
Source: Iran MO 2019 , secound round , day 2 , p5
May 3, 2019
combinatoricsGame Theoryalgebra
Problem Statement
Ali and Naqi are playing a game. At first, they have Polynomial .
Naqi starts. In each turn one can choice natural number in his trun, and add to the polynomial. For example after 2 moves can be : . If after Ali's turn, there exist such that then Ali loses the game. Prove that Ali can play forever somehow he never loses the game!