bestTimetoBuyandSellStock.js

//////////////////////////////////////////////Best Time to Buy and Sell Stock/////////////////////////////////////////////////
// You are given an array prices where prices[i] is the price of a given stock on the ith day.
// You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.
// Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.
// Example 1:
//
// Input: prices = [7,1,5,3,6,4]
// Output: 5
// Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
// Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
// Example 2:
//
// Input: prices = [7,6,4,3,1]
// Output: 0
// Explanation: In this case, no transactions are done and the max profit = 0.
// Constraints:
// 1 <= prices.length <= 105
// 0 <= prices[i] <= 104
// Accepted
// 1,687,889
// Submissions
// 3,181,117
// Seen this question in a real interview before?
const maxProfit = function(prices) {
    let max = 0, maxEnd = 0, minPrice = prices[0];

    for(let i = 0; i < prices.length; i++){
        maxEnd = Math.max(0, prices[i] - minPrice);
        minPrice = Math.min(minPrice, prices[i]);
        max =  Math.max(maxEnd, max);
    }

    return max;
};

// console.log(maxProfit([7,1,5,3,6,4]));
// console.log(maxProfit([7,6,4,3,1]));