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Best Time to Buy and Sell Stock

Problem statement​

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: 5Explanation: 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: 0Explanation: In this case, no transactions are done and the max profit = 0.

Constraints:

  • 1 <= prices.length <= 105
  • 0 <= prices[i] <= 104

My solution​

/**
 * @param {number[]} prices
 * @return {number}
 */
var maxProfit = function(prices) {
    let minValue;
    let maxValue = 0
    
    for (const price of prices) {
        if (minValue === undefined || price < minValue) {
            minValue = price
        } else {
            maxValue = Math.max(maxValue, price - minValue)
        }
    }
    
    return maxValue
};