C. Propagating tree
time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of n nodes numbered from 1 to n, each node i having an initial value ai. The root of the tree is node 1.

This tree has a special property: when a value val is added to a value of node i, the value -val is added to values of all the children of node i. Note that when you add value -val to a child of node i, you also add -(-val) to all children of the child of node i and so on. Look an example explanation to understand better how it works.

This tree supports two types of queries:

  • "1 x val" — val is added to the value of node x;
  • "2 x" — print the current value of node x.

In order to help Iahub understand the tree better, you must answer m queries of the preceding type.

Input

The first line contains two integers n and m (1 ≤ n, m ≤ 200000). The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 1000). Each of the next n–1 lines contains two integers vi and ui (1 ≤ vi, ui ≤ n), meaning that there is an edge between nodes vi and ui.

Each of the next m lines contains a query in the format described above. It is guaranteed that the following constraints hold for all queries: 1 ≤ x ≤ n, 1 ≤ val ≤ 1000.

Output

For each query of type two (print the value of node x) you must print the answer to the query on a separate line. The queries must be answered in the order given in the input.

Examples
Input
5 5
1 2 1 1 2
1 2
1 3
2 4
2 5
1 2 3
1 1 2
2 1
2 2
2 4
Output
3
3
0
Note

The values of the nodes are [1, 2, 1, 1, 2] at the beginning.

Then value 3 is added to node 2. It propagates and value -3 is added to it's sons, node 4 and node 5. Then it cannot propagate any more. So the values of the nodes are [1, 5, 1,  - 2,  - 1].

Then value 2 is added to node 1. It propagates and value -2 is added to it's sons, node 2 and node 3. From node 2 it propagates again, adding value 2 to it's sons, node 4 and node 5. Node 3 has no sons, so it cannot propagate from there. The values of the nodes are [3, 3,  - 1, 0, 1].

You can see all the definitions about the tree at the following link: http://en.wikipedia.org/wiki/Tree_(graph_theory)

思路:dfs序+线段树;

首先dfs序映射一下,然后转换成然后线段树维护,新然后开两个数组,一个作为正一个作为负。

复杂度n×log(n);

  1 #include<stdio.h>
2 #include<algorithm>
3 #include<queue>
4 #include<stdlib.h>
5 #include<iostream>
6 #include<string.h>
7 #include<set>
8 #include<map>
9 #include<vector>
10 using namespace std;
11 typedef long long LL;
12 int ans[200005];
13 int id[200005];
14 int a[200005];
15 typedef vector<int> Ve;
16 vector<Ve>vec(200005);
17 bool flag[200005];
18 int cn = 0;
19 int l[200005];
20 int r[200005];
21 void dfs(int n,int p);
22 int tree1[200005*4];
23 int tree2[4*200005];
24 void update(int x,int n,int c);
25 int ask(int x);
26 int jiou[200005];
27 void update(int l,int r,int k,int nn,int mm,int co,int p)
28 {
29 if(l > mm||r < nn)
30 {
31 return ;
32 }
33 else if(l <= nn&& r >= mm)
34 {
35 if(p%2)tree1[k]+=co;
36 else tree2[k]+=co;
37 return ;
38 }
39 else
40 {
41 update(l,r,2*k+1,nn,(nn+mm)/2,co,p);
42 update(l,r,2*k+2,(nn+mm)/2+1,mm,co,p);
43 }
44 }
45 int ask1(int l,int r,int k,int nn,int mm)
46 {
47 if(l > mm || r < nn)
48 return 0;
49 else if(l <= nn&&r >= mm)
50 {
51 return tree1[k];
52 }
53 else
54 {
55 tree1[2*k+1] += tree1[k];
56 tree1[2*k+2] += tree1[k];
57 tree1[k] = 0;
58 int nx = ask1(l,r,2*k+1,nn,(nn+mm)/2);
59 int ny = ask1(l,r,2*k+2,(nn+mm)/2+1,mm);
60 return nx + ny;
61 }
62 }
63 int ask2(int l,int r,int k,int nn,int mm)
64 {
65 if(l > mm || r < nn)
66 return 0;
67 else if(l <= nn&&r >= mm)
68 {
69 return tree2[k];
70 }
71 else
72 {
73 tree2[2*k+1] += tree2[k];
74 tree2[2*k+2] += tree2[k];
75 tree2[k] = 0;
76 int nx = ask2(l,r,2*k+1,nn,(nn+mm)/2);
77 int ny = ask2(l,r,2*k+2,(nn+mm)/2+1,mm);
78 return nx + ny;
79 }
80 }
81 int main(void)
82 {
83 int n,m;
84 scanf("%d %d",&n,&m);
85 for(int i = 1; i <= n; i++)
86 {
87 scanf("%d",&a[i]);
88 }
89 for(int i = 1; i < n; i++)
90 {
91 int x,y;
92 scanf("%d %d",&x,&y);
93 vec[x].push_back(y);
94 vec[y].push_back(x);
95 }
96 dfs(1,1);
97 for(int i = 1; i <= n; i++)
98 id[ans[i]] = i;
99 while(m--)
100 {
101 int val;
102 int co,ic;
103 scanf("%d %d",&val,&ic);
104 if(val == 1)
105 {
106 scanf("%d",&co);
107 update(l[ic],r[ic],0,1,cn,co,jiou[ic]);
108 }
109 else
110 {
111 int xx = ask1(id[ic],id[ic],0,1,cn);
112 int yy = ask2(id[ic],id[ic],0,1,cn);
113 //printf("%d\n",xx);
114 if(jiou[ic]%2)
115 {
116 printf("%d\n",xx-yy+a[ic]);
117 }
118 else printf("%d\n",yy-xx+a[ic]);
119 }
120 }
121 return 0;
122 }
123 void dfs(int n,int p)
124 {
125 flag[n] = true;
126 ans[++cn] = n;
127 l[n] = cn;
128 jiou[n] = p;
129 for(int i = 0; i < vec[n].size(); i++)
130 {
131 int x = vec[n][i];
132 if(!flag[x])
133 dfs(x,p+1);
134 }
135 r[n] = cn;
136 }

C. Propagating tree的更多相关文章

  1. Codeforces Round #225 (Div. 1) C. Propagating tree dfs序+树状数组

    C. Propagating tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/383/p ...

  2. Codeforces Round #225 (Div. 2) E. Propagating tree dfs序+-线段树

    题目链接:点击传送 E. Propagating tree time limit per test 2 seconds memory limit per test 256 megabytes inpu ...

  3. AC日记——Propagating tree Codeforces 383c

    C. Propagating tree time limit per test 2 seconds memory limit per test 256 megabytes input standard ...

  4. CodeForces 383C Propagating tree

    Propagating tree Time Limit: 2000ms Memory Limit: 262144KB This problem will be judged on CodeForces ...

  5. Codeforces Round #225 (Div. 1) C. Propagating tree dfs序+ 树状数组或线段树

    C. Propagating tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/383/p ...

  6. 题解 CF383C 【Propagating tree】

    这道题明明没有省选难度啊,为什么就成紫题了QAQ 另:在CF上A了但是洛谷Remote Judge玄学爆零. 思路是DFS序+线段树. 首先这道题直观上可以对于每一次修改用DFS暴力O(n),然后对于 ...

  7. codeforces 383C Propagating tree 线段树

    http://codeforces.com/problemset/problem/383/C 题目就是说,  给一棵树,将一个节点的值+val, 那么它的子节点都会-val, 子节点的子节点+val. ...

  8. Codeforces 383C . Propagating tree【树阵,dfs】

    标题效果: 有一棵树,有两种操作模式对本树:1:表示为(1 x val),在NOx加在节点上val,然后x每个节点加上儿子- val.给每个儿子一个儿子在一起-(- val),加到没有儿子为止.2:表 ...

  9. CodeForces 384E Propagating tree (线段树+dfs)

    题意:题意很简单么,给定n个点,m个询问的无向树(1为根),每个点的权值,有两种操作, 第一种:1 x v,表示把 x 结点加上v,然后把 x 的的子结点加上 -v,再把 x 的子结点的子结点加上 - ...

随机推荐

  1. 什么是DDL,DML,DCL

    转载自  https://www.2cto.com/database/201610/555167.html DML.DDL.DCL区别 . 总体解释: DML(data manipulation la ...

  2. python函数初体验

    函数 函数参数w 形式参数>>>>(被指定具体的值)默认参数, 实际参数是调用时候的实际指定参数 我们把函数⾥⾯的参数叫形式函数,函数实际调⽤的时候,赋予的参数叫实际函数 定义 ...

  3. 学习java 7.14

    学习内容: 标准输入输出流 输出语言的本质:是一个标准的输出流 字节打印流 字符打印流 对象序列化流 明天内容: 进程和线程 遇到问题: 用对象序列化流序列化一个对象后,假如我们修改了对象所属的类文件 ...

  4. c++ cmake及包管理工具conan简单入门

    cmake是一个跨平台的c/c++工程管理工具,可以通过cmake轻松管理我们的项目 conan是一个包管理工具,能够自动帮助我们下载及管理依赖,可以配合cmake使用 这是一个入门教程,想深入了解的 ...

  5. Zookeeper之创建组,加入组,列出组成员和删除组

    public class CreateGroup implements Watcher { private static final int SESSION_TIMEOUT=5000; //ZooKe ...

  6. 【编程思想】【设计模式】【行为模式Behavioral】模板模式Template

    Python转载版 https://github.com/faif/python-patterns/blob/master/behavioral/template.py #!/usr/bin/env ...

  7. go goroutines 使用小结

    go +方法 就实现了一个并发,但由于环境不同,需要对并发的个数进行限制,限制同一时刻并发的个数,后面称此为"并发限流". 为什么要并发限流? 虽然GO M+P+G的方式号称可以轻 ...

  8. Function overloading and const keyword

    Predict the output of following C++ program. 1 #include<iostream> 2 using namespace std; 3 4 c ...

  9. springboot+vue脚手架使用nginx前后端分离

    1.vue配置 /** * * 相对于该配置的nginx服务器请参考nginx配置文件 * */ module.exports = { // 基本路径 publicPath: '/', // 输出文件 ...

  10. Spring Batch(8) -- Listeners

    September 29, 2020 by Ayoosh Sharma In this article, we will take a deep dive into different types o ...