Find best profitable stock sale

Write an efficient function that takes stock Prices Yesterday and returns the best profit I could have made from 1 purchase and 1 sale of 1 ABC stock yesterday.

The indices are the time in minutes past trade opening time, which was 9:30am local time.

The values are the price in dollars of ABC stock at that time.

So if the stock cost $100 at 10:30am, stockPricesYesterday[60] = 100.

Solution#1:

public class Solution {

    public static int getMaxProfit (int[] yesterdayPrices) {

        int[] bestDeal= new int[]{-1,-1};

        int bestDealPrice =0;

        for(int i =0; i++; i <= yesterdayPrices.length - 1)

        {

            for (int j= i+1; j++; j <= yesterdayPrices.length)

            {

                if(bestDealPrice < (a[i]-a[j]))

                {

                    bestDeal[0]=i;

                    bestDeal[1]=j;

                    bestDealPrice=(a[i]-a[j]);

                }

            }

        }

        return bestDealPrice;

    }

    public static void main(String[] args) {

        // run your function through some test cases here

        // remember: debugging is half the battle!

        int[] stockPricesYesterday = new int[]{12, 6, 8, 4, 11, 9};

        System.out.println(getMaxProfit(stockPricesYesterday));

    }

}

Solution#2:

    public static int getMaxProfit (int[] yesterdayPrices) {

    int minAvailablePrice = yesterdayPrices[0];

    int maximumProfit = yesterdayPrices[1] - yesterdayPrices[0];

    for (int i = 1; i < stockPricesYesterday.length; i++) {

        int currentPrice = yesterdayPrices[i];

        int potentialProfit = currentPrice - minPrice;

        maximumProfit = Math.max(maximumProfit, potentialProfit);

        minAvailablePrice = Math.min(minAvailablePrice, currentPrice);

    }

    return maximumProfit;

}