Given a array of numbers representing the stock prices of a company in chronological order, write a function that calculates the maximum profit you could have made from buying and selling that stock once. You must buy before you can sell it. For example, given [9, 11, 8, 5, 7, 10], you should return 5, since you could buy the stock at 5 dollars …

daily-coding-problem-47.rb

def maximum_profit stock
    max = 0 
    stock.each_with_index do |buy, i|
        (i+1...stock.size).each do |sell|
            profit = stock[sell] - buy
            max = profit if profit > max
        end 
    end 
    return max
end 

stock = [9, 11, 8, 5, 7, 10]
puts maximum_profit stock