Best Time to Buy and Sell Stock I 题目: 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 algo…

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…

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…

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 algorithm…

1.  String to Integer (atoi) Implement atoi to convert a string to an integer. Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases. Notes: It is inte…

这三道题都是同一个背景下的变形:给定一个数组,数组里的值表示当日的股票价格,问你如何通过爱情买卖来发家致富? best time to buy and sell stock i: 最多允许买卖一次 best time to buy and sell stock ii: 不限制买卖次数 best time to buy and sell stock iii:最多允许买卖两次 对于i: 思路就是在第i个位置抛出时,希望在0~i-1个位置上的最低价买入,才能使得第i个位置的收益最大.然后比较所有可以抛…

Best Time to Buy and Sell Stock I 题目链接 题目要求: 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…

题记:在求最大最小值的类似题目中,递推思想的奇妙之处,在于递推过程也就是比较求值的过程,从而做到一次遍历得到结果. LeetCode 上面的这三道题最能展现递推思想的美丽之处了. 题1 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 complet…

一.Best Time to Buy and Sell Stock I 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 algori…

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 algorithm…

Best Time to Buy and Sell Stock I 你只能一个操作:维修preMin拍摄前最少发生值 代码例如以下: int maxProfit(vector<int> &prices) { if (prices.size() == 0) return 0; int profit = 0; int preMin = prices[0]; for (int i = 1; i < prices.size(); i++) { if (prices[i] < pre…

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. 找到最大…

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 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…

问题: 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)…

123. Best Time to Buy and Sell Stock III 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 mul…

122. 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 on…

121. 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 algor…

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 two transactions. Note: You may not engage in multiple transactions at the same time…

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 as many transactions as you like (ie, buy one and sell one share of the stock multiple times)…

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">leetcode第188题,Best Time to Buy and Sell Stock IV题目如下:</span> https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv/ Say you hav…

Best Time to Buy and Sell Stock III 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. 现在A股涨这么好,要是股票都提前知道价格就好了(@_@) 首先,考虑如…

将Best Time to Buy and Sell Stock的如下思路用到此题目 思路1:第i天买入,能赚到的最大利润是多少呢?就是i + 1 ~ n天中最大的股价减去第i天的. 思路2:第i天买出,能赚到的最大利润是多少呢?就是第i天的价格减去 0~ i-1天中最小的. 和前两道题比起来的话,这道题最难了,因为限制了交易次数.解决问题的途径我想出来的是:既然最多只能完成两笔交易,而且交易之间没有重叠,那么就divide and conquer.设i从0到n-1,那么针对每一个i,看看在pr…

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. 解题思路: https://leetcode.com/discuss/18330/is-it-best-solution-with-o-n-o-1…

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 two transactions. Note:You may not engage in multiple transactions at the same time (…

题目要求: 最多交易两次,并且只能买卖完之后再买. 总思路: 在数组中找一个适当的点i,使得i左右两边profit之和最大. 思路: 1.从左往右扫描,left[i]记录包括i元素以内的左部的maxprofit,用Best Time to Buy and Sell Stock 1可得到. 2.从右往左扫描,right[i]记录i+1到尾部元素的maxprofit,将上面的low改成big即可 3.返回max(left[i],right[i]) 注意: 1.考虑好,包括i与不包括i的情况 2.考虑…

这两个系列的题目其实是同一套题,可以互相转换. 首先我们定义一个数组: prefixSum (前序和数组) Given nums: [1, 2, -2, 3] prefixSum: [0, 1, 3, 1, 4 ] 现在我们发现对prefixSum做Best Time To Buy And Sell Stock和对nums做Maximum Subarray,结果相同. 接下来我们就利用prefixSum解这两个系列的题目. Maximum Subarray Question Given an a…