It looks to me like you are just splattering code around without a clue as to what you are doing.
main does not terminate correctly.
display has a body, even though it is NOT a function declaration.
getch() returns a value that you discard. It won't work on an Arduino, anyway, since the Arduino doesn't have a keyboard.
printf() won't work, because the Arduino doesn't have a console.
You have no clue when to use { and }, and when not to.