121.best-time-to-buy-and-sell-stock.131502194.ac.java

class Solution {
    public int maxProfit(int[] prices) {
        int maxProfit = 0;
        if (prices.length == 0) {
            return maxProfit;
        }
        
        int minSoFar = prices[0];
        for (int i = 1; i < prices.length; i++) {
            maxProfit = Math.max(maxProfit, prices[i] - minSoFar);
            minSoFar = Math.min(minSoFar, prices[i]);
        }
        
        return maxProfit;
    }
}