Submission #607731

#	Time	Username	Problem	Language	Result	Execution time	Memory
607731		abcvuitunggio	Birthday gift (IZhO18_treearray)	C++17	100 / 100	965 ms	80424 KiB

treearray

#include <iostream>
#include <vector>
#include <set>
using namespace std;
int n,m,q,p[200001][20],t,l,r,k,st[200001],en[200001],id,a[200001],u,v;
vector <int> ke[200001];
set <int> s[200001],s2[200001];
void dfs(int u, int par){
    st[u]=++id;
    for (int v:ke[u])
        if (v!=par){
            p[v][0]=u;
            dfs(v,u);
        }
    en[u]=++id;
}
void prep(){
    for (int i=1;i<20;i++)
        for (int j=1;j<=n;j++)
            p[j][i]=p[p[j][i-1]][i-1];
}
bool isancestor(int i, int j){
    return (st[i]<=st[j]&&en[i]>=en[j]);
}
int lca(int i, int j){
    if (isancestor(i,j))
        return i;
    if (isancestor(j,i))
        return j;
    for (int k=19;k>=0;k--)
        if (p[i][k]&&!isancestor(p[i][k],j))
            i=p[i][k];
    return p[i][0];
}
int main(){
    ios_base::sync_with_stdio(NULL);cin.tie(nullptr);
    cin >> n >> m >> q;
    for (int i=1;i<n;i++){
        cin >> u >> v;
        ke[u].push_back(v);
        ke[v].push_back(u);
    }
    dfs(1,1);
    prep();
    for (int i=1;i<=m;i++){
        cin >> a[i];
        s[a[i]].insert(i);
        if (i>1)
            s2[lca(a[i-1],a[i])].insert(i-1);
    }
    while (q--){
        cin >> t >> l >> r;
        if (t==1){
            s[a[l]].erase(l);
            if (l<m)
                s2[lca(a[l],a[l+1])].erase(l);
            if (l>1)
                s2[lca(a[l-1],a[l])].erase(l-1);
            a[l]=r;
            s[a[l]].insert(l);
            if (l<m)
                s2[lca(a[l],a[l+1])].insert(l);
            if (l>1)
                s2[lca(a[l-1],a[l])].insert(l-1);
            continue;
        }
        cin >> k;
        if (!s[k].empty()&&(*--s[k].end())>=l){
            int x=*s[k].lower_bound(l);
            if (x<=r){
                cout << x << ' ' << x << '\n';
                continue;
            }
        }
        if (!s2[k].empty()&&(*--s2[k].end())>=l){
            int x=*s2[k].lower_bound(l);
            if (x<r){
                cout << x << ' ' << x+1 << '\n';
                continue;
            }
        }
        cout << "-1 -1\n";
    }
}

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