一个系列三道题,我都不会做,google之答案.过了两道,第三道看不懂,放置,稍后继续. 一.Best Time to Buy and Sell Stock I 题目:一个数组表示一支股票的价格变换.要求只买卖一次,获得最大收益. 思路:一开始我认为是寻找最大.最小值,但由于最大值不一定总是出现在最小值的后面,因此WA. 参考思路:DP.对第i个价格,减去前i-1个价格中的最小值(保证该收益是在第i个价格卖出的最大收益),其收益与之前获得的最大收益相比. 代码: public int maxPr…

LeetCode:Best Time to Buy and Sell Stock Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an a…

思路: 1. 算法导论讲 divide and conquer 时, 讲到过这个例子. 书中的做法是先让 price 数组减去一个值, 然后求解最大连续子数组的和. 分治算法的复杂度为 o(nlogn) 2. 剑指 offer 来给出最大连续子数组和的动态规划做法, 时间复杂度缩小到 o(n) 3. 此题不必转化为最大连续子数组和问题, 可以直接使用动态规划解法(我不知道如何转化).  假设 dp[i] 表示第 i 天把股票卖出获得的最大收益, 那么可以根据 price[i] 和 price[i…

Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times) wit…

Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most k transactions. Note:You may not engage in multiple transactions at the same time (ie, yo…

Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most two transactions. Note:You may not engage in multiple transactions at the same time (ie,…

Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times). Ho…

Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit. 这道题相…

Best Time to Buy and Sell Stock II Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one sha…

原题链接在这里:https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv/ 题目: Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most k transacti…