Submission #978892

#TimeUsernameProblemLanguageResultExecution timeMemory
978892irmuunBirthday gift (IZhO18_treearray)C++17
30 / 100
4049 ms10196 KiB
#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const int N=2e5+5;

int n,m,q,a[N],par[N][20],dep[N];
vector<int>adj[N];
void dfs(int x,int p){
    par[x][0]=p;
    for(int y:adj[x]){
        if(y!=p){
            dep[y]=dep[x]+1;
            dfs(y,x);
        }
    }
}
int up(int x,int d){
    for(int i=19;i>=0;i--){
        if(d&(1<<i)){
            x=par[x][i];
        }
    }
    return x;
}
int lca(int x,int y){
    if(dep[x]<dep[y]) swap(x,y);
    x=up(x,dep[x]-dep[y]);
    for(int i=19;i>=0;i--){
        if(par[x][i]!=par[y][i]){
            x=par[x][i];
            y=par[y][i];
        }
    }
    if(x!=y) x=par[x][0];
    return x;
}

struct segtree{
    int n;
    vector<int>d;
    segtree(int n):n(n){
        d.resize(4*n);
        build(1,1,n);
    }
    void build(int node,int l,int r){
        if(l==r){
            d[node]=0;
            return;
        }
        int mid=(l+r)/2;
        build(node*2,l,mid);
        build(node*2+1,mid+1,r);
        d[node]=0;
    }
    int query(int node,int l,int r,int L,int R){
        if(l>r||r<L||R<l) return 0;
        if(L<=l&&r<=R){
            return d[node];
        }
        int mid=(l+r)/2;
        int le=query(node*2,l,mid,L,R),ri=query(node*2+1,mid+1,r,L,R);
        if(le==0) return ri;
        if(ri==0) return le;
        return lca(le,ri);
    }
    void update(int node,int l,int r,int pos,int val){
        if(r<pos||pos<l) return;
        if(l==r){
            d[node]=val;
            return;
        }
        int mid=(l+r)/2;
        update(node*2,l,mid,pos,val);
        update(node*2+1,mid+1,r,pos,val);
        if(d[node*2]==0) d[node]=d[node*2+1];
        if(d[node*2+1]==0) d[node]=d[node*2];
        d[node]=lca(d[node*2],d[node*2+1]);
    }
}sg(N);

void ask(int l,int r,int u){
    for(int x=l;x<=r;x++){
        int cur=a[x];
        int L=x,R=r;
        while(L<R){
            int mid=(L+R+1)/2;
            int node=sg.query(1,1,N,x,mid);
            if(dep[node]<dep[u]){
                R=mid-1;
            }
            else{
                L=mid;
            }
        }
        if(sg.query(1,1,N,x,L)==u){
            cout<<x<<' '<<L<<"\n";
            return;
        }
    }
    cout<<"-1 -1\n";
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    cin>>n>>m>>q;
    for(int i=1;i<n;i++){
        int u,v;
        cin>>u>>v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    for(int i=1;i<=m;i++){
        cin>>a[i];
    }
    dep[1]=0;
    dfs(1,1);
    for(int j=1;j<20;j++){
        for(int i=1;i<=n;i++){
            par[i][j]=par[par[i][j-1]][j-1];
        }
    }
    for(int i=1;i<=m;i++){
        sg.update(1,1,N,i,a[i]);
    }
    while(q--){
        int t;
        cin>>t;
        if(t==1){
            int pos,v;
            cin>>pos>>v;
            a[pos]=v;
            sg.update(1,1,N,pos,v);
        }
        else{
            int l,r,u;
            cin>>l>>r>>u;
            ask(l,r,u);
        }
    }
}

Compilation message (stderr)

treearray.cpp: In function 'void ask(int, int, int)':
treearray.cpp:91:13: warning: unused variable 'cur' [-Wunused-variable]
   91 |         int cur=a[x];
      |             ^~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...