stocks.java

// Justin Raczak
// This program calculates the max one-day increase of a stock price over a 10-day period.
import java.util.*;

class Increase {

    public static void main(String [] args) {

        // Set up the Scanner
        Scanner scanner = new Scanner(System.in);

        // Store the price of the low day in the biggest one-day increase
        int dayOnePrice = 0;
        // Store the numerical day for the low price
        int dayOne = 0;

        // Store the price of the high day in the biggest one-day increase
        int dayTwoPrice = 0;
        // Store the numerical day for the high price
        int dayTwo = 0;

        // Store the previous new price we saw so we can deterime if it's part of a larger one-day increase
        int previousDayPrice = 0;
        // Store the numerical day for the previous day
        int previousDay = 0;

        for (int i = 1; i <= 10; i++) {
            // Ask the user for 10 stock prices
            System.out.print("Please input the price of the stock on day " + i + " of the desired time period: ");
            int newPrice = scanner.nextInt();

            // If we haven't stored any values yet, store days 1 and 2 without any comparison
            if (i < 3) {
                if (i == 1) {
                    dayOnePrice = newPrice;
                    dayOne = i;
                } else {
                    dayTwoPrice = newPrice;
                    previousDayPrice = newPrice;
                    dayTwo = i;
                    previousDay = i;
                }

                // Compare the price changes between the current day and previous day and currently stored first and second days
                // If the new difference is greater, replace the stored data. If not, stash the new price as the previous day and continue
            } else {
                if ((newPrice - previousDayPrice) > (dayTwoPrice - dayOnePrice)) {
                    dayOnePrice = previousDayPrice;
                    dayOne = previousDay;
                    dayTwoPrice = newPrice;
                    dayTwo = i;
                } else {
                    previousDayPrice = newPrice;
                    previousDay = i;
                }
            }
        }
        if ((dayTwoPrice - dayOnePrice) == 0) {
            System.out.print("The price of this stock never increased. (bummer)");
        } else {
            System.out.print("The highest price increase of $" + (dayTwoPrice - dayOnePrice) + " occurred between days " + dayOne + " and " + dayTwo + ".");
        }
    }
}