Best Time to Buy and Sell Stock - DSA Array Question

Maximizing Profit: A Guide to the Best Time to Buy and Sell Stock Using Java

Introduction: In the world of stock trading, timing is everything. Investors constantly seek optimal moments to buy and sell stocks to maximize their profits. One popular problem in algorithmic trading is determining the best time to buy and sell stock to achieve the highest possible profit. In this article, we will delve into the "Best Time to Buy and Sell Stock" problem and explore a solution using Java programming language.

Understanding the Problem: The "Best Time to Buy and Sell Stock" problem entails finding the maximum profit that can be achieved by buying and selling a stock at most once. Given an array of stock prices where the index represents the day and the value represents the price of the stock on that day, our goal is to determine the maximum profit that can be attained.

Approach: We can solve this problem efficiently using a simple one-pass algorithm. The key idea is to iterate through the array of stock prices while keeping track of the minimum price seen so far and updating the maximum profit accordingly.

Java Code Implementation:

public class BestTimeToBuyAndSellStock {

    public int maxProfit(int[] prices) {
        if (prices == null || prices.length <= 1)
            return 0;

        int minPrice = prices[0];
        int maxProfit = 0;

        for (int i = 1; i < prices.length; i++) {
            if (prices[i] < minPrice) {
                minPrice = prices[i];
            } else {
                int profit = prices[i] - minPrice;
                if (profit > maxProfit) {
                    maxProfit = profit;
                }
            }
        }

        return maxProfit;
    }

    public static void main(String[] args) {
        int[] prices = {7, 1, 5, 3, 6, 4};
        BestTimeToBuyAndSellStock solution = new BestTimeToBuyAndSellStock();
        System.out.println("Maximum Profit: " + solution.maxProfit(prices));
    }
}

Explanation of the Code:

• The maxProfit method takes an array of stock prices as input and returns the maximum profit that can be achieved.

• It initializes variables minPrice to the first element of the prices array and maxProfit to 0.

• It then iterates through the prices array starting from the second element.

• Within each iteration, it checks if the current price is lower than the minPrice. If so, it updates minPrice to the current price.

• If the current price is higher than or equal to minPrice, it calculates the profit by subtracting minPrice from the current price.

• If the calculated profit is greater than maxProfit, it updates maxProfit with the new profit.

• Finally, it returns maxProfit after traversing the entire array.

Conclusion: In this article, we explored the "Best Time to Buy and Sell Stock" problem and provided a Java solution to efficiently determine the maximum profit. By employing a one-pass algorithm, we can effectively identify the optimal buying and selling times, enabling investors to make informed decisions and maximize their returns in the stock market. Happy trading!