IMO 2015 Shortlist A2

Determine all functions f : Z Ñ Z with the property that f x ´ fpyq ˘ “ f fpxq ˘ ´ fpyq ´ 1 holds for all x,y P Z. (Croa...

IMO 2015 Shortlist A2

Category: Algebra

Problem

Determine all functions f : Z Ñ Z with the property that f x ´ fpyq ˘ “ f fpxq ˘ ´ fpyq ´ 1 holds for all x,y P Z. (Croatia)