Submission #942865

#	Time	Username	Problem	Language	Result	Execution time	Memory
942865		bachhoangxuan	Arboras (RMI20_arboras)	C++17	100 / 100	295 ms	23520 KiB

arboras

// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/
#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
#define int long long
#define ld long double
#define pii pair<int,int>
#define piii pair<int,pii>
#define mpp make_pair
#define fi first
#define se second
const int inf=1e18;
const int mod=1e9+7;
const int maxn=100005;
const int B=650;
const int maxs=655;
const int maxm=200005;
const int maxq=1000005;
const int maxl=25;
const int maxa=1000000;
const int root=3;
const int base=101;

int n,q,par[maxn],d[maxn],dep[maxn];
vector<int> edge[maxn];
int L[maxn],R[maxn],cn[maxn],T;
int nxt[maxn],total=0;

struct node{
    int mx=0,u=-1;
    node(int mx=-1,int u=-1):mx(mx),u(u){}
    bool operator<(const node &a)const{
        if(mx!=a.mx) return mx<a.mx;
        else return u<a.u;
    }
};

int lazy[4*maxn];
node tree[4*maxn];
void update(int l,int r,int id,int tl,int tr,int val){
    if(tr<l || r<tl) return;
    if(tl<=l && r<=tr){
        lazy[id]+=val;
        tree[id].mx+=val;
        return;
    }
    int mid=(l+r)>>1;
    update(l,mid,id<<1,tl,tr,val);update(mid+1,r,id<<1|1,tl,tr,val);
    tree[id]=max(tree[id<<1],tree[id<<1|1]);
    tree[id].mx+=lazy[id];
}
node query(int l,int r,int id,int tl,int tr){
    if(tr<l || r<tl || tl>tr) return node();
    if(tl<=l && r<=tr) return tree[id];
    int mid=(l+r)>>1;
    node res=max(query(l,mid,id<<1,tl,tr),query(mid+1,r,id<<1|1,tl,tr));
    res.mx+=lazy[id];
    return res;
}
void build(int l,int r,int id){
    if(l==r){
        tree[id]=node(d[cn[l]],cn[l]);
        return;
    }
    int mid=(l+r)>>1;
    build(l,mid,id<<1);build(mid+1,r,id<<1|1);
    tree[id]=max(tree[id<<1],tree[id<<1|1]);
}

node dfs(int u){
    L[u]=++T;cn[T]=u;
    d[u]+=d[par[u]];
    dep[u]=dep[par[u]]+1;
    node cc=node(d[u],u);
    for(int v:edge[u]) cc=max(cc,dfs(v));
    nxt[cc.u]=u;R[u]=T;
    return cc;
}
int getChild(int u,int x){
    int l=0,r=(int)edge[u].size()-1;
    while(l<r){
        int mid=(l+r+1)>>1;
        int v=edge[u][mid];
        if(L[v]<=L[x]) l=mid;
        else r=mid-1;
    }
    return edge[u][l];
}
node getMax(int u){
    return query(1,n,1,L[u],R[u]);
}
node getSec(int u){
    if(edge[u].empty()) return query(1,n,1,L[u],L[u]);
    node Max=getMax(u);
    int v=getChild(u,Max.u);
    return max(query(1,n,1,L[u],L[v]-1),query(1,n,1,R[v]+1,R[u]));
}

void solve(){
    cin >> n;
    for(int i=2;i<=n;i++){
        cin >> par[i];par[i]++;
        edge[par[i]].push_back(i);
    }
    for(int i=2;i<=n;i++) cin >> d[i];
    dfs(1);
    build(1,n,1);
    for(int i=1;i<=n;i++){
        //cout << i << endl;
        total+=(getMax(i).mx+getSec(i).mx-2*d[i])%mod;
        total=(total%mod+mod)%mod;
    }
    cout << total << '\n';
    cin >> q;
    for(int i=1;i<=q;i++){
        int u,val;cin >> u >> val;u++;
        node cc=getMax(u);
        //cout << '*' << cc.u << ' ' << cc.mx << '\n';
        total=(total+(dep[u]-dep[nxt[cc.u]])*val)%mod;
        cc.mx+=val;
        int v=nxt[cc.u];
        while(v>1){
            int p=par[v];
            node cur=getMax(p);
            if(cc<cur){
                node c2=getSec(p);
                if(c2<cc) total=(total+cc.mx-c2.mx)%mod;
                break;
            }
            else{
                total=(total+cur.mx-getSec(p).mx)%mod;
                int x=nxt[cur.u];
                total=(total+(cc.mx-cur.mx)%mod*(dep[v]-dep[x]))%mod;
                nxt[cur.u]=getChild(p,cur.u);
                nxt[cc.u]=x;v=x;
            }
        }
        cout << (total%mod+mod)%mod << '\n';
        update(1,n,1,L[u],R[u],val);
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    int test=1;//cin >> test;
    while(test--) solve();
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 31 / 31
• Subtask 4: 45 / 45