Alyona and a tree
time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Alyona has a tree with n vertices. The root of the tree is the vertex 1. In each vertex Alyona wrote an positive integer, in the vertex i she wrote ai. Moreover, the girl wrote a positive integer to every edge of the tree (possibly, different integers on different edges).

Let's define dist(v, u) as the sum of the integers written on the edges of the simple path from v to u.

The vertex v controls the vertex u (v ≠ u) if and only if u is in the subtree of v and dist(v, u) ≤ au.

Alyona wants to settle in some vertex. In order to do this, she wants to know for each vertex v what is the number of vertices u such thatv controls u.

Input

The first line contains single integer n (1 ≤ n ≤ 2·105).

The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 109) — the integers written in the vertices.

The next (n - 1) lines contain two integers each. The i-th of these lines contains integers pi and wi (1 ≤ pi ≤ n, 1 ≤ wi ≤ 109) — the parent of the (i + 1)-th vertex in the tree and the number written on the edge between pi and (i + 1).

It is guaranteed that the given graph is a tree.

Output

Print n integers — the i-th of these numbers should be equal to the number of vertices that the i-th vertex controls.

Examples
input
5
2 5 1 4 6
1 7
1 1
3 5
3 6
output
1 0 1 0 0
input
5
9 7 8 6 5
1 1
2 1
3 1
4 1
output
4 3 2 1 0
Note

In the example test case the vertex 1 controls the vertex 3, the vertex 3 controls the vertex 5 (note that is doesn't mean the vertex 1controls the vertex 5).

分析:对每一个点,如果他与祖先的距离小于自身权值,则对祖先贡献+1,问最后所有点的答案数;

   如果这个点对"他自己的祖先"的祖先有贡献,那么显然对"他自己的祖先"也是有贡献的;

   所以考虑倍增(二分)求出这个点p能到达最远祖先q的地方,那么ans[p父亲~q]++;

   考虑前缀和,即ans[p父亲]++,ans[q父亲]--,最后dfs处理前缀和即可;

代码:

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <climits>
#include <cstring>
#include <string>
#include <set>
#include <map>
#include <unordered_map>
#include <queue>
#include <stack>
#include <vector>
#include <list>
#define rep(i,m,n) for(i=m;i<=n;i++)
#define rsp(it,s) for(set<int>::iterator it=s.begin();it!=s.end();it++)
#define mod 1000000007
#define inf 0x3f3f3f3f
#define vi vector<int>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ll long long
#define pi acos(-1.0)
#define pii pair<int,int>
#define Lson L, mid, ls[rt]
#define Rson mid+1, R, rs[rt]
#define sys system("pause")
#define intxt freopen("in.txt","r",stdin)
const int maxn=2e5+;
using namespace std;
int gcd(int p,int q){return q==?p:gcd(q,p%q);}
ll qpow(ll p,ll q){ll f=;while(q){if(q&)f=f*p;p=p*p;q>>=;}return f;}
inline ll read()
{
ll x=;int f=;char ch=getchar();
while(ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}
while(ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}
return x*f;
}
int n,m,k,t,fa[][maxn],ans[maxn],dep[maxn],a[maxn];
ll w[][maxn];
vector<pii>e[maxn];
void dfs(int p)
{
for(int i=;fa[i-][fa[i-][p]];i++)
{
fa[i][p]=fa[i-][fa[i-][p]];
w[i][p]=w[i-][p]+w[i-][fa[i-][p]];
}
for(pii x:e[p])
{
int to=x.fi,q=x.se;
if(to==fa[][p])continue;
dep[to]=dep[p]+;
fa[][to]=p;
w[][to]=q;
dfs(to);
}
}
void dfs1(int now,int pre)
{
for(pii x:e[now])
{
if(x.fi!=pre)
{
dfs1(x.fi,now);
ans[now]+=ans[x.fi];
}
}
}
int query(int p,int pos)
{
for(int i=;i>=;i--)
if(w[i][pos]&&w[i][pos]<=p)p-=w[i][pos],pos=fa[i][pos];
return pos;
}
int main()
{
int i,j;
dep[]=;
scanf("%d",&n);
rep(i,,n)scanf("%d",&a[i]);
rep(i,,n-)scanf("%d%d",&j,&k),e[j].pb(mp(i+,k)),e[i+].pb(mp(j,k));
dfs();
rep(i,,n)
{
int q=query(a[i],i);
ans[fa[][i]]++;
ans[fa[][q]]--;
}
dfs1(,);
rep(i,,n)printf("%d ",ans[i]);
//system("Pause");
return ;
}

Alyona and a tree的更多相关文章

  1. Codeforces Round #381 (Div. 2)D. Alyona and a tree(树+二分+dfs)

    D. Alyona and a tree Problem Description: Alyona has a tree with n vertices. The root of the tree is ...

  2. codeforces 381 D Alyona and a tree(倍增)(前缀数组)

    Alyona and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standard i ...

  3. Codeforces Round #381 (Div. 1) B. Alyona and a tree dfs序 二分 前缀和

    B. Alyona and a tree 题目连接: http://codeforces.com/contest/739/problem/B Description Alyona has a tree ...

  4. Codeforces Round #381 (Div. 2) D. Alyona and a tree 树上二分+前缀和思想

    题目链接: http://codeforces.com/contest/740/problem/D D. Alyona and a tree time limit per test2 secondsm ...

  5. CodeForces 682C Alyona and the Tree (树+dfs)

    Alyona and the Tree 题目链接: http://acm.hust.edu.cn/vjudge/contest/121333#problem/C Description Alyona ...

  6. Codeforces Round #358 (Div. 2) C. Alyona and the Tree 水题

    C. Alyona and the Tree 题目连接: http://www.codeforces.com/contest/682/problem/C Description Alyona deci ...

  7. Codeforces Round #381 (Div. 2) D. Alyona and a tree dfs序+树状数组

    D. Alyona and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standar ...

  8. Codeforces Round #358 (Div. 2) C. Alyona and the Tree dfs

    C. Alyona and the Tree time limit per test 1 second memory limit per test 256 megabytes input standa ...

  9. XJOI 3363 树4/ Codeforces 739B Alyona and a tree(树上差分+路径倍增)

    D. Alyona and a tree time limit per test  2 seconds memory limit per test  256 megabytes input  stan ...

随机推荐

  1. Ubuntu 16.04安装和配置Sublime Text 3

    1.安装Sublime Text 3 首先添加sublime text 3的仓库: sudo add-apt-repository ppa:webupd8team/sublime-text-3 根据提 ...

  2. 4天html总结

  3. TOMcat9 免安装版的配置

    在这里默认大家都安装了jdk并且配置了java的环境,网上教程很多. 在tomcat官网(http://tomcat.apache.org/download-90.cgi)上下载和自己系统匹配的安装包 ...

  4. Leetcode - 186 Reverse Words in a String II

    题目: Given an input string, reverse the string word by word. A word is defined as a sequence of non-s ...

  5. Request for the permission of type异常

    调用wcf调用的时候引发一个错误,错误信息如下: <Message>Request for the permission of type 'System.Configuration.Con ...

  6. incredibuild agent service is not running

    incredibuild 不用介绍了,今天因为服务没有启动报错显示为: incredibuild agent service is not running 解决方法为: 在Incredibuild的安 ...

  7. Python基础篇-day7

    本节目录-面向对象1 类介绍1.1 面向对象oo特征1.2 类的特性1.3 创建与调用 1.3.1 基本结构 1.3.2 结构说明 1.3.3 对外部提供只读访问接口 1.3.4 析构方法2 继承2. ...

  8. linux的命令使用记录

    iptables禁止53端口的出包(dns) iptables -A OUTPUT -p udp --dport 53 -j DROP linux查看网络监听端口 netstat -npl 文件复制 ...

  9. 顺序栈和链式栈(C++实现)

    顺序栈,是一种基于数组的存储表示. 实现类代码如下: template<class T> class SeqStack{ T *element; int top; int maxSize; ...

  10. Oracle 四种列转行的方法

    1. Oracle自带列转行函数listagg: 实例: with temp as( select 'China' nation ,'Guangzhou' city from dual union a ...