按紫书来注意这道题的题目给了很大的方便,就相当于验证k是不是答案,不是的话就是k+1 #include<iostream> #include<string> #include<cstring> #include<sstream> #include<vector> #include<algorithm> using namespace std; + ; ; struct Edge { int u, v, d; // d=1 means…

 UVa 1380 A Scheduling Problem 题目: http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=41557 思路:   给出一个任务调度树,单向边u->v表示u必须在v之前完成,双向边u-v表示无所谓方向. 题目给出定理,首先dfs求得忽略无向边后的最长链点数k,那么问题就是判断是否可以通过无向边定向从而使得最长链点数不超过k.用dp的判断. 设f[i]表示以i为根的子树中所有的边定向后最长链点数不超过…

A Scheduling Problem   Description There is a set of jobs, say x1, x2,..., xn <tex2html_verbatim_mark>, to be scheduled. Each job needs one day to complete. Your task is to schedule the jobs so that they can be nished in a minimum number of days. Th…

题目链接:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=4126 $LRJ$紫书例题$9-26$ 题目大意: 给定一颗树 有些边已经标好方向 现在要给其余的边标上方向 使得最长的有向链最短 $HIT:$ 题目额外给了一个结论 假设已经确定方向的边所能得到的最长链为$k$ 最后的最长链一定$k$ 或$k + 1$ 不知道是自己太久没有写树形…

图片加载可能有点慢,请跳过题面先看题解,谢谢 题目给出了一个信息:答案是有向边最长路 \(k\) 的值或者是 \(k+1\) 的值 那么题目就变成了:求是否有一种给无向边定向的方案,使得在以有向边最长路的起点为根的树(其实也并不是一棵树,只是当成一棵树来处理)内,点的深度在 \([1,k]\) 内 如果存在这样的方案,答案为 \(k\) ,否则答案为 \(k+1\) \(k\) 的值和有向边最长路的起点我们可以暴力 \(dfs\) 在 \(O(n)\) 的时间内求出来 关键是怎么求方案? $ $…

翻译 有 \(3\) 个正整数 \(a\).\(b\).\(c\),请你输出这 \(3\) 个数中的最大值 \(-\) 最小值的差. 分析 求最大值 \(-\) 最小值的差,我们自然可以使用 for 循环进行判断,但在这里介绍一种新方法,C++ 中的 max 函数与 min 函数,它的格式如下: cout<<min(a,b); cout<<max(a,b); 知道它的格式以后,不难写出程序. #include <bits/stdc++.h> using namespac…

Machine Schedule Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 13731   Accepted: 5873 Description As we all know, machine scheduling is a very classical problem in computer science and has been studied for a very long history. Scheduli…

Machine Schedule Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 8404    Accepted Submission(s): 4215 Problem Description As we all know, machine scheduling is a very classical problem in comput…

We began our study of algorithmic techniques with greedy algorithms, which in some sense form the most natural approach to algorithm design. Faced with a new computational problem, we've seen that it's not hard to propose multiple possible greedy alg…

Time Limit: 1000 MS Memory Limit: 10000 KB 64-bit integer IO format: %I64d , %I64u   Java class name: Main [Submit] [Status] [Discuss] Description As we all know, machine scheduling is a very classical problem in computer science and has been studied…