[LeetCode Top Interview 150] [Array & String] 121. Best Time to Buy and Sell Stock

시간초과 1

/**
 * @param {number[]} prices
 * @return {number}
 */
var maxProfit = function(prices) {
    let max = 0;
    let profit = 0;
    let profitrArr = [];

    if(prices.length === 1) return 0

    for (let i = 0; i < prices.length - 1; i++) {
        max = Math.max(...prices.slice(i + 1, prices.length + 1));

        if (max - prices[i] > 0) profitrArr.push(max - prices[i]);

    }
    profit = Math.max(...profitrArr);

    if (profitrArr.length === 0) return 0;

    return profit;
};

시간초과 2

/**
 * @param {number[]} prices
 * @return {number}
 */
var maxProfit = function(prices) {
    if (prices.length === 1) return 0;

    let temp = 0;
    let j;
    for (let i = 0; i < prices.length - 1; i++) {
        for (j = 1; j < prices.length; j++) {
            if (j > i && prices[j] - prices[i] > temp)
                temp = prices[j] - prices[i];
        }
    }

    return temp;
};

성공

/**
 * @param {number[]} prices
 * @return {number}
 */
var maxProfit = function(prices) {
    if (prices.length === 1) return 0;

    let left = 0;
    let right = 1;
    let temp = 0;

    while (right < prices.length) {
        if (prices[right] > prices[left])
            temp = Math.max(temp, prices[right] - prices[left]);
        else left = right;
        right++;
    }

    return temp;
};