Submission #379401

#	Time	Username	Problem	Language	Result	Execution time	Memory
379401		jass921026	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1080 ms	68076 KiB

treearray

#include<bits/stdc++.h>
using namespace std;
#define jizz ios_base::sync_with_stdio(false);cin.tie(NULL);
typedef long long ll;
typedef pair<int,int> pii;
#define F first
#define S second
#define ALL(x) (x).begin(),(x).end()
#define pb push_back
#define mkp make_pair
const int MAXN=2E5+10;
vector<int> G[MAXN];
set<int> st[MAXN];
int n, m, q, arr[2*MAXN], anc[20][MAXN], dep[MAXN];
void dfs(int x, int f){
    anc[0][x]=f;
    dep[x]=dep[f]+1;
    for(auto i:G[x]){
        if(i==f) continue;
        dfs(i,x);
    }
}
int lca(int u, int v){
    if(dep[u]<dep[v]) swap(u,v);
    int b=dep[u]-dep[v];
    for(int c=0;b>0;c++){
        if(b%2){
            u=anc[c][u];
        }
        b/=2;
    }
    if(u==v) return u;
    for(int i=__lg(n)+1;i>=0;i--){
        if(anc[i][u]!=anc[i][v]){
            u=anc[i][u];
            v=anc[i][v];
        }
    }
    return anc[0][u];
}
int main(){ jizz
    cin>>n>>m>>q;
    for(int i=0;i<n-1;i++){
        int a, b;
        cin>>a>>b;
        G[a].pb(b);
        G[b].pb(a);
    }
    dfs(1,0);
    for(int i=1;(1<<i)<=n;i++){
        for(int j=1;j<=n;j++){
            anc[i][j]=anc[i-1][anc[i-1][j]];
        }
    }
    for(int i=0;i<m;i++){
        cin>>arr[2*i];
    }
    for(int i=0;i<m-1;i++){
        arr[2*i+1]=lca(arr[2*i],arr[2*i+2]);
    }
    for(int i=0;i<2*m-1;i++){
        st[arr[i]].insert(i);
    }
    for(int i=0;i<q;i++){
        int type;
        cin>>type;
        if(type==1){
            int pos, v;
            cin>>pos>>v;
            int p=2*(pos-1);
            st[arr[p]].erase(p);
            arr[p]=v;
            st[arr[p]].insert(p);
            if(p>0){
                st[arr[p-1]].erase(p-1);
                int c=lca(arr[p-2],v);
                arr[p-1]=c;
                st[arr[p-1]].insert(p-1);
            }
            if(p<2*(m-1)){
                st[arr[p+1]].erase(p+1);
                int c=lca(v,arr[p+2]);
                arr[p+1]=c;
                st[arr[p+1]].insert(p+1);
            }
        } else if(type==2){
            int l, r, v;
            cin>>l>>r>>v;
            l=2*(l-1), r=2*(r-1);
            auto p=st[v].lower_bound(l);
            if(p==st[v].end()) cout<<"-1 -1\n";
            else if((*p)>r) cout<<"-1 -1\n";
            else if((*p)%2) cout<<(*p)/2+1<<" "<<(*p)/2+2<<"\n";
            else cout<<(*p)/2+1<<" "<<(*p)/2+1<<"\n";
        }
    }
    return 0;
}
/*
5 4 4
1 2
3 1
3 4
5 3
4 5 2 3
2 1 3 1
1 3 5
2 3 4 5
2 1 3 1
*/

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 44 / 44