Submission #751439

#	Time	Username	Problem	Language	Result	Execution time	Memory
751439		sofija6	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1160 ms	99760 KiB

treearray

#include <bits/stdc++.h>
#define ll long long
#define MAXN 200010
#define logn 18
using namespace std;
vector<ll> G[MAXN];
set<ll> poslca[MAXN],posv[MAXN];
ll a[MAXN],up[MAXN][logn],in[MAXN],out[MAXN],t;
void DFS(ll i,ll p)
{
    in[i]=t++;
    up[i][0]=p;
    for (ll j=1;j<logn;j++)
        up[i][j]=up[up[i][j-1]][j-1];
    for (ll next : G[i])
    {
        if (next!=p)
            DFS(next,i);
    }
    out[i]=t++;
}
bool Is_Ancestor(ll u,ll v)
{
    return in[u]<=in[v] && out[u]>=out[v];
}
ll LCA(ll u,ll v)
{
    if (Is_Ancestor(u,v))
        return u;
    if (Is_Ancestor(v,u))
        return v;
    for (ll i=logn-1;i>=0;i--)
    {
        if (!Is_Ancestor(up[u][i],v))
            u=up[u][i];
    }
    return up[u][0];
}
int main()
{
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll n,m,q,u,v,type,pos,l,r;
    cin >> n >> m >> q;
    for (ll i=1;i<n;i++)
    {
        cin >> u >> v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    DFS(1,1);
    for (ll i=1;i<=m;i++)
    {
        cin >> a[i];
        if (i>1)
            poslca[LCA(a[i-1],a[i])].insert(i-1);
        posv[a[i]].insert(i);
    }
    while (q--)
    {
        cin >> type;
        if (type==1)
        {
            cin >> pos >> v;
            if (pos>1)
            {
                poslca[LCA(a[pos-1],a[pos])].erase(pos-1);
                poslca[LCA(a[pos-1],v)].insert(pos-1);
            }
            if (pos<m)
            {
                poslca[LCA(a[pos],a[pos+1])].erase(pos);
                poslca[LCA(v,a[pos+1])].insert(pos);
            }
            posv[a[pos]].erase(pos);
            posv[v].insert(pos);
            a[pos]=v;
            continue;
        }
        cin >> l >> r >> v;
        auto it=posv[v].lower_bound(l);
        if (it!=posv[v].end() && *it<=r)
        {
            cout << *it << " " << *it << "\n";
            continue;
        }
        it=poslca[v].lower_bound(l);
        if (it==poslca[v].end() || *it>=r)
            cout << -1 << " " << -1 << "\n";
        else
            cout << *it << " " << *it+1 << "\n";
    }
    return 0;
}

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