121. Best time to buy Stock problem

121-leetcode-best-time-to-buy-stock.java

class Solution {
    public int maxProfit(int[] prices) {
        int maxProfit = 0;
        int prevBuy = Integer.MAX_VALUE;
        int maxSellPrice = Integer.MIN_VALUE;
        for (int buyDay=0; buyDay < prices.length; buyDay++) {
            int buyPrice = prices[buyDay];
            if (buyPrice >= prevBuy && maxSellPrice >= buyPrice) {
                continue;
            }
            
            maxSellPrice = prices[buyDay];
            for (int sellDay = buyDay+1; sellDay < prices.length; sellDay++) {
                maxSellPrice = Math.max(maxSellPrice, prices[sellDay]);
            }
            maxProfit = Math.max(maxProfit, maxSellPrice-buyPrice);
            prevBuy = buyPrice;
            
        }
        return maxProfit;
    }
}