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. 汽车C2M模式综述

  2. Python序列化,json&pickle&shelve模块

    1. 序列化说明 序列化可将非字符串的数据类型的数据进行存档,如字典.列表甚至是函数等等 反序列化,将通过序列化保存的文件内容反序列化即可得到数据原本的样子,可直接使用 2. Python中常用的序列 ...

  3. 【模板】最小费用最大流(网络流)/洛谷P3381

    题目链接 https://www.luogu.com.cn/problem/P3381 题目大意 输入格式 第一行包含四个正整数 \(n,m,s,t\),分别表示点的个数.有向边的个数.源点序号.汇点 ...

  4. Mybatis相关知识点(二)

    Mybatis解决jdbc编程的问题 1. 数据库连接创建.释放频繁造成系统资源浪费从而影响系统性能,如果使用数据库连接池可解决此问题. 解决:在SqlMapConfig.xml中配置数据连接池,使用 ...

  5. Android数据存取

    Android数据存取 一.SharedPreferencesc存取数据 SharedPreferences是使用键值对的方式来存储数据的,也就是在保存一条数据时,需要给这条数据提供一个对应的键,这样 ...

  6. Oracle异常处理——ORA-01502:索引或这类索引的分区处于不可用状态

    Oracle异常处理--ORA-01502:索引或这类索引的分区处于不可用状态参考自:https://www.cnblogs.com/lijiaman/p/9277149.html 1.原因分析经过查 ...

  7. mysql锁相关讲解及其应用

    一.mysql的锁类型 了解Mysql的表级锁 了解Mysql的行级锁 (1) 共享/排它锁(Shared and Exclusive Locks) 共享锁和排他锁是InnoDB引擎实现的标准行级别锁 ...

  8. 接口测试 python+PyCharm 环境搭建

    1.配置Python环境变量 a:我的电脑->属性->高级系统设置->环境变量->系统变量中的PATH变量. 变量名:PATH      修改变量值为:;C:\Python27 ...

  9. js调用高德地图API获取地理信息进行定位

    <script type="text/javascript" src="http://webapi.amap.com/maps?v=1.3&key=(需要自 ...

  10. JS - 字符串转换成数组,数组转换成字符串

    1.字符串转换成数组: var arr = "1, 2, 3, 4, 5, 6"; arr.split(","); // ["1",&quo ...