Best Time to Buy and Sell Stockeasy

/**
 * @param {number[]} prices
 * @return {number}
 */
function maxProfit(prices) {
    // TODO: find the maximum profit from a single buy/sell
    return 0;
}

console.log(maxProfit([7, 1, 5, 3, 6, 4])); // 5
console.log(maxProfit([7, 6, 4, 3, 1]));     // 0