/*
 * @lc app=leetcode id=121 lang=java
 *
 * [121] Best Time to Buy and Sell Stock
 */

// @lc code=start
class Solution {
    public int maxProfit(int[] prices) {
        if(prices == null || prices.length == 0) {
            return 0;
        }   
        int min = prices[0], profit = 0;
        for(int i=1; i<prices.length; i++) {
            profit = Math.max(profit, prices[i] - min);
            min = Math.min(min, prices[i]);
        }
        return profit;
    }
}
// @lc code=end