题解 | #买卖股票的最好时机(一)#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param prices int整型一维数组 
     * @return int整型
     */
    public int maxProfit (int[] prices) {
        // write code here

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

        int[] maxProfits = new int[prices.length];
        // maxProfits[i] represents the maximum profit that can be made from selling the stock on day i 
        
        int min = prices[0];

        int result = Integer.MIN_VALUE;
        for (int i = 1; i <= prices.length - 1; ++i) {
            maxProfits[i] = prices[i] - min;
            min = Math.min(prices[i], min);

            result = Math.max(maxProfits[i], result);
        }
        

        if (result > 0) {
            return result;
        } else {
            return 0;
        }
    }
}