nim_game.rb

# You are playing the following Nim Game with your friend: There is a heap of stones on the table, each 
# time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the winner. 
# You will take the first turn to remove the stones.

# Both of you are very clever and have optimal strategies for the game. Write a function to determine 
# whether you can win the game given the number of stones in the heap.

# For example, if there are 4 stones in the heap, then you will never win the game: no matter 1, 2, or 3 stones 
# you remove, the last stone will always be removed by your friend.

def can_win_nim(n)
    n % 4 == 0 ? false : true
end