题意: \(n\)个物品,每个物品有一个价格,买一个高价格的物品,可以选择免费得到一个价格严格低于这个物品的物品.求得到\(n\)个物品的最小代价. 题解: 神仙贪心-- 题目要求求出最小代价,相当于求最多能免费拿的价格. 先考虑一个\(n^2\)的DP:将物品按价格从高到低排序.把相同价格的物品放在一起处理.\(f[i][j]\)表示DP到第\(i\)位,免费拿了\(j\)个物品,最大能节约的价格. 那么已经原价买了但还没有送东西的物品有\(i - 2 * j\)个,我们称这些物品为可用物品.…

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…

找到最低值和最高值 int maxProfit(vector<int>& prices) { ); ; ]; ;i<prices.size();i++) { profit=max(profit,prices[i]-cur_min);//记录最大利润 cur_min=min(cur_min,prices[i]);//保留购买最小值 } return profit; } 2. 计算差分序列,大于0加入 int maxProfit(vector<int>& pric…

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. 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…