zoukankan      html  css  js  c++  java
  • On Changing Tree

    C. On Changing Tree
    time limit per test
    2 seconds
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    You are given a rooted tree consisting of n vertices numbered from 1 to n. The root of the tree is a vertex number 1.

    Initially all vertices contain number 0. Then come q queries, each query has one of the two types:

    • The format of the query: v x k. In response to the query, you need to add to the number at vertex v number x; to the numbers at the descendants of vertex v at distance 1, add x - k; and so on, to the numbers written in the descendants of vertex v at distance i, you need to add x - (i·k). The distance between two vertices is the number of edges in the shortest path between these vertices.
    • The format of the query: v. In reply to the query you should print the number written in vertex v modulo 1000000007 (109 + 7).

    Process the queries given in the input.

    Input

    The first line contains integer n (1 ≤ n ≤ 3·105) — the number of vertices in the tree. The second line contains n - 1 integers p2, p3, ... pn(1 ≤ pi < i), where pi is the number of the vertex that is the parent of vertex i in the tree.

    The third line contains integer q (1 ≤ q ≤ 3·105) — the number of queries. Next q lines contain the queries, one per line. The first number in the line is type. It represents the type of the query. If type = 1, then next follow space-separated integers v, x, k (1 ≤ v ≤ n0 ≤ x < 109 + 7; 0 ≤ k < 109 + 7). If type = 2, then next follows integer v (1 ≤ v ≤ n) — the vertex where you need to find the value of the number.

    Output

    For each query of the second type print on a single line the number written in the vertex from the query. Print the number modulo 1000000007 (109 + 7).

    Examples
    input
    Copy
    3
    1 1
    3
    1 1 2 1
    2 1
    2 2
    output
    Copy
    2
    1
    Note

    You can read about a rooted tree here: http://en.wikipedia.org/wiki/Tree_(graph_theory).

    #pragma GCC optimize(2)
    
    #include <bits/stdc++.h>
    #define lowbit(x) x&(-x)
    using namespace std;
    const int maxn = 1e6 + 108;
    typedef long long ll;
    const ll mod=1e9+7;
    
    int n,q;
    int fa[maxn],dfn[maxn],siz[maxn],dep[maxn];
    vector<int>e[maxn];
    
    inline int dfs(int cur){
        static int tot=0;
        dfn[cur]=++tot;
        for(register int i=0;i<e[cur].size();++i){
            int to=e[cur][i];
            siz[cur]+=dfs(to);
        }
        //printf("debug dfn[%d] = %d
    ",cur,dfn[cur]);
        return ++siz[cur];
    }
    
    struct BIT{
        ll o[maxn];
        inline void init(){
            memset(o,0,sizeof(o));
        }
        inline void update(int pos,ll val){
            while(pos<=n){
                o[pos]=(o[pos]+val)%mod;
                pos+=lowbit(pos);
            }
        }
    
        inline ll query(int pos){
            ll res=0;
            while(pos){
                res=(res+o[pos])%mod;
                pos-=lowbit(pos);
            }
            return res%mod;
        }
    
    }atom1,atom2;
    
    
    
    int main() {
    #ifndef ONLINE_JUDGE
        freopen("1.txt", "r", stdin);
    #endif
        scanf("%d",&n);
        for(register int i=2;i<=n;++i){
            scanf("%d",&fa[i]);
            e[fa[i]].emplace_back(i);
            dep[i]=dep[fa[i]]+1;
        }
        atom1.init();
        atom2.init();
        dfs(1);
        scanf("%d",&q);
        int type,v,x;
        ll k;
        while(q--){
            scanf("%d",&type);
            if(type==1){
                scanf("%d%d%lld",&v,&x,&k);
                atom1.update(dfn[v],x+dep[v]*k%mod);
                atom1.update(dfn[v]+siz[v],mod-(x+dep[v]*k%mod)%mod);
                atom2.update(dfn[v],k);
                atom2.update(dfn[v]+siz[v],(mod-k%mod)%mod);
            }
            else{
                scanf("%d",&v);
                printf("%lld
    ",(atom1.query(dfn[v])%mod-dep[v]*atom2.query(dfn[v])%mod+mod)%mod);
            }
        }
        return 0;
    }
  • 相关阅读:
    字典的操作用法小总结
    HTTP Headers解析
    RStdio常用快捷键
    R语言数据类型
    数据科学实战手册(R+Python)书中引用资料网址
    ggplot2使用初探
    urllib2使用初探
    R语言以及RStdio的安装
    目标检测--Selective Search for Object Recognition(IJCV, 2013)
    关于Python的lambda
  • 原文地址:https://www.cnblogs.com/czy-power/p/11457057.html
Copyright © 2011-2022 走看看