121 Best Time to Buy and Sell Stock

Are you looking to improve your skills in solving algorithmic problems using JavaScript? If so, you’ve come to the right place! In this tutorial, we’ll walk through the solution for the “121 Best Time to Buy and Sell Stock” problem on LeetCode, providing an easy explanation along the way.

Problem Description

The problem “121 Best Time to Buy and Sell Stock” asks us to find the maximum profit that can be obtained by buying and selling a single stock on specific days. We are given an array of stock prices, where the i-th element represents the price of the stock on day i.

JavaScript Solution

Let’s start by defining a JavaScript function that takes an array of stock prices as the input and returns the maximum profit. At each step, we’ll update two variables: minPrice to track the lowest stock price we’ve seen so far, and maxProfit to track the maximum profit we can achieve.

    
      function maxProfit(prices) {
        let minPrice = Infinity;
        let maxProfit = 0;
        
        for (let i = 0; i < prices.length; i++) {
          if (prices[i]  maxProfit) {
            maxProfit = prices[i] - minPrice;
          }
        }
        
        return maxProfit;
      }
  
  

Easy Explanation

The logic behind the solution is straightforward. We iterate through the array of stock prices, updating minPrice to the lowest price seen so far and maxProfit to the maximum profit that can be achieved. By the end of the iteration, we’ll have the maximum profit possible from buying and selling the stock.

Conclusion

With the power of JavaScript and an understanding of the problem, solving the “121 Best Time to Buy and Sell Stock” becomes a manageable task. We hope this tutorial has provided you with a clear explanation of the problem and its solution.