描述There is a company that has N employees(numbered from 1 to N),every employee in the company has a immediate boss (except for the leader of whole company).If you are the immediate boss of someone,that person is your subordinate, and all his subordin…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3974 给你T组数据,n个节点,n-1对关系,右边的是左边的父节点,所有的值初始化为-1,然后给你q个操作: 有两种操作: 操作一:T X Y ,将以X为根的子树上的所有节点都变成Y. 操作二:C X,查询第X号点是多少? 没想到是线段树做,就算想到了也想不到用dfs序做... 例子中给你了这样的树: 2 /     \ 3       5 /    \ 4      1 DFS一遍转化成DFS序:2…

题目大意:公司里有一些员工及对应的上级,给出一些员工的关系,分配给某员工任务后,其和其所有下属都会进行这项任务.输入T表示分配新的任务, 输入C表示查询某员工的任务.本题的难度在于建树,一开始百思不得其解,后来看了lx大大的博客后才明白,用递归建立了各个员工之间的关系,Start[x] 表示x员工为Boss的起点,End[x]表示x员工为Boss的终点.之后对这样的整体线段进行赋值即可. #include <stdio.h> #include <algorithm> #includ…

POJ.3321 Apple Tree ( DFS序 线段树 单点更新 区间求和) 题意分析 卡卡屋前有一株苹果树,每年秋天,树上长了许多苹果.卡卡很喜欢苹果.树上有N个节点,卡卡给他们编号1到N,根的编号永远是1.每个节点上最多结一个苹果.卡卡想要了解某一个子树上一共结了多少苹果. 现在的问题是不断会有新的苹果长出来,卡卡也随时可能摘掉一个苹果吃掉.你能帮助卡卡吗? 前缀技能 边表存储树 DFS时间戳 线段树 首先利用边表将树存储下来,然后DFS打上时间戳.打上时间戳之后,我们就知道书上节点对…

http://acm.hdu.edu.cn/showproblem.php?pid=3974 Assign the task Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 7144    Accepted Submission(s): 2708 Problem Description There is a company that h…

There is a company that has N employees(numbered from 1 to N),every employee in the company has a immediate boss (except for the leader of whole company).If you are the immediate boss of someone,that person is your subordinate, and all his subordinat…

Assign the task Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 636    Accepted Submission(s): 322 Problem Description There is a company that has N employees(numbered from 1 to N),every employ…

题意:给定一棵树的公司职员管理图,有两种操作, 第一种是 T x y,把 x 及员工都变成 y, 第二种是 C x 询问 x 当前的数. 析:先把该树用dfs遍历,形成一个序列,然后再用线段树进行维护,很简单的线段树. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib>…

题目链接:https://vjudge.net/problem/HDU-3974 There is a company that has N employees(numbered from 1 to N),every employee in the company has a immediate boss (except for the leader of whole company).If you are the immediate boss of someone,that person is…

题意: 一个公司有n个员工,每个员工都有一个上司,一个人下属的下属也是这个人的下属,因此可将他们的关系看成一棵树, 然后给定两种操作,C操作是查询当前员工的工作,T操作是将y工作分配给x员工,当一个人得到y工作时,他的 员工也会得到这个工作,即这个点和他的子树的工作都变成y. 链接: http://acm.hdu.edu.cn/showproblem.php?pid=3974 思路: 先一遍dfs求出该员工掌管的员工区间,每次修改时用线段树修改这个区间的员工即可,而查询时只要查询l_[x](该员…