题目描述 Farmer John has N cows that need to be milked (1 <= N <= 10,000), each of which takes only one unit of time to milk. Being impatient animals, some cows will refuse to be milked if Farmer John waits too long to milk them. More specifically, cow…

原题链接https://www.lydsy.com/JudgeOnline/problem.php?id=4096 容易想到的一个测略就是,优先考虑结束时间小的牛.所以我们对所有牛按照结束时间排序.然后我们发现前\(i\)头奶牛在时刻j的最大价值由前\(i-1\)头奶牛在时刻\(j-1\)的最大价值转移过来,那么考虑dp. 设\(dp[i][j]\)表示前i头奶牛在时刻j的最大价值,那么我们有: \[dp[i][j]=max(dp[i][j],dp[i-1][j-1]+g[i]); \] 然后考…

洛谷题目链接:[USACO06DEC]牛奶模式Milk Patterns 题目描述 Farmer John has noticed that the quality of milk given by his cows varies from day to day. On further investigation, he discovered that although he can't predict the quality of milk from one day to the next,…

P2949 [USACO09OPEN]工作调度Work Scheduling 题目描述 Farmer John has so very many jobs to do! In order to run the farm efficiently, he must make money on the jobs he does, each one of which takes just one time unit. His work day starts at time 0 and has 1,000…

P2949 [USACO09OPEN]工作调度Work Scheduling 题目描述 Farmer John has so very many jobs to do! In order to run the farm efficiently, he must make money on the jobs he does, each one of which takes just one time unit. His work day starts at time 0 and has 1,000…

题目描述 Farmer John's N cows (1 <= N <= 10,000) are conveniently numbered 1..N. Each cow i takes T(i) units of time to milk. Unfortunately, some cows must be milked before others, owing to the layout of FJ's barn. If cow A must be milked before cow B,…

链接 其实在博客园里写题解都挺应付的都是在洛谷写了之后 挑一部分粘过来 在洛谷写的也都是废话,是为了凑篇幅 主要就是代码 大体思路就一提 这题贪心不行废话 跑m遍SPFA更新最小值 注意数组记得清空 The Last: #include <queue> #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std;…

P3063 [USACO12DEC]牛奶的路由Milk Routing 题目背景 征求翻译.如果你能提供翻译或者题意简述,请直接发讨论,感谢你的贡献. 题目描述 Farmer John's farm has an outdated network of M pipes (1 <= M <= 500) for pumping milk from the barn to his milk storage tank. He wants to remove and update most of the…

题目描述 由于乳制品产业利润很低,所以降低原材料(牛奶)价格就变得十分重要.帮助Marry乳业找到最优的牛奶采购方案. Marry乳业从一些奶农手中采购牛奶,并且每一位奶农为乳制品加工企业提供的价格是不同的.此外,就像每头奶牛每天只能挤出固定数量的奶,每位奶农每天能提供的牛奶数量是一定的.每天Marry乳业可以从奶农手中采购到小于或者等于奶农最大产量的整数数量的牛奶. 给出Marry乳业每天对牛奶的需求量,还有每位奶农提供的牛奶单价和产量.计算采购足够数量的牛奶所需的最小花费. 注:每天所有奶农…

Portal Description 给出一个\(n(n\leq4\times10^4)\)个数的数列\(\{a_n\}(a_i\geq1)\).一个数列的最大贡献定义为其中若干个不相邻的数的和的最大值.进行\(m(m\leq5\times10^4)\)次操作,每次修改数列中的一个数并询问此时的最大贡献. Solution 线段树. 对于线段树上每个节点\([L,R]\),维护四个值\(f_{00},f_{01},f_{10},f_{11}\),分别表示\(a_L,a_R\)都不选,不选\(a_…