Submission #500225

#	Time	Username	Problem	Language	Result	Execution time	Memory
500225		nickmet2004	Birthday gift (IZhO18_treearray)	C++11	100 / 100	1244 ms	87128 KiB

treearray

#include<bits/stdc++.h>

using namespace std;
const int N = 2e5 + 5;
int n , m , q , a[N];
vector<int> adj[N];
int P[N][20],depth[N];
set<int> A[N] , B[N];
void dfs(int u , int p = 0){
    P[u][0] = p;
    for(int i = 1; i <= 18; ++i)P[u][i] = P[P[u][i - 1]][i - 1];
    for(int v : adj[u]){
        if(v==p)continue;
        depth[v]=depth[u]+1;
        dfs(v , u);
    }
}
int LCA(int u , int v){
    if(depth[u] < depth[v])swap(u , v);
    int k = depth[u] - depth[v];
    for(int i = 18; ~i; --i){
        if(k>>i&1) u = P[u][i];
    }
    if(u==v)return u;
    for(int i= 18; ~i; --i){
        if(P[u][i] != P[v][i]) u = P[u][i] , v= P[v][i];
    }
    return P[u][0];
}
void upd(int pos , int v){
    int y;
    if(pos >1){
        y = LCA(a[pos - 1] ,a[pos]);
        A[y].erase(pos - 1);
        A[LCA(a[pos - 1] , v)].insert(pos - 1);
    }
    if(pos < m){
        y = LCA(a[pos] , a[pos + 1]);
        A[y].erase(pos);
        A[LCA(a[pos+1] , v)].insert(pos);
    }
    B[a[pos]].erase(pos);
    B[v].insert(pos);
    a[pos]=v;
    return;
}
void get(int l , int r , int v){
    auto it = B[v].lower_bound(l);
    if(it != B[v].end() && *it <= r){
        cout << *it << " " << *it << endl;
        return;
    }
    it = A[v].lower_bound(l);
    if(it != A[v].end() && *it + 1 <= r){
        cout << *it << " " << *it + 1<<endl;
        return;
    }
    cout<<-1 << " " << -1<<endl;
}
int main (){
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n >> m>>q;
    int u  ,v;
    for(int i= 1; i< n; ++i){
        cin >> u >> v;
        adj[u].emplace_back(v);adj[v].emplace_back(u);
    }
    for(int i= 1; i<= m; ++i)cin >> a[i];
    dfs(1);
    for(int i= 1; i <= m; ++i){
        int X = LCA(a[i] , a[i + 1]);
        if(i<m)A[X].insert(i);
        B[a[i]].insert(i);
    }
    while(q--){
        int x;
        cin >> x;
        if(x==1){
            int pos , v;
            cin >> pos >> v;
            upd(pos , v);
        }else{
            int l , r ,v;
            cin >> l >> r >> v;
            get( l  , r , v);
        }
    }
}

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