Algorithms—121.Best Time to Buy and Sell Stock

思路：很典型的一题，不细说了

public class Solution {    public int maxProfit(int[] prices) {if (prices.length <= 1) {return 0;}int[] change = new int[prices.length - 1];for (int i = 0; i < change.length; i++) {change[i] = prices[i + 1] - prices[i];}int sum = 0;int s = 0;int begin = 0;int end = 0;for (int i = 0; i < change.length; i++) {s += change[i];if (s < 0) {s = 0;begin = i + 1;end = i + 1;}if (change[i] > 0) {end = i;}if (s > sum) {sum = s;}}return sum;}}