Submission #874900

#	Time	Username	Problem	Language	Result	Execution time	Memory
874900		12345678	Birthday gift (IZhO18_treearray)	C++17	56 / 100	171 ms	1052 KiB

treearray

#include <bits/stdc++.h>

using namespace std;

const int nx=2e3+5, kx=11;
int n, m, q, u, v, lvl[nx], pa[nx][kx], t, l, r, vl, x;
vector<int> d[nx], a(nx);

void dfs(int u, int p)
{
    lvl[u]=lvl[p]+1;
    pa[u][0]=p;
    for (int i=1; i<kx; i++) pa[u][i]=pa[pa[u][i-1]][i-1];
    for (auto v:d[u]) if (v!=p) dfs(v, u);
}

int lca(int u, int v)
{
    if (lvl[u]>lvl[v]) swap(u, v);
    for (int i=kx-1; i>=0; i--) if (lvl[pa[v][i]]>=lvl[u]) v=pa[v][i];
    if (u==v) return u;
    for (int i=kx-1; i>=0; i--) if (pa[u][i]!=pa[v][i]) u=pa[u][i], v=pa[v][i];
    return pa[u][0];
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m>>q;
    for (int i=0; i<n-1; i++) cin>>u>>v, d[u].push_back(v), d[v].push_back(u);
    dfs(1, 1);
    for (int i=1; i<=m; i++) cin>>a[i];
    while (q--)
    {
        cin>>t;
        if (t==1) cin>>x>>vl, a[x]=vl;
        else
        {
            cin>>l>>r>>vl;
            int c=-1, idx=l;
            for (int i=l; i<=r; i++)
            {
                if (c==-1) c=a[i];
                else c=lca(c, a[i]);
                if (c==vl)
                {
                    cout<<idx<<' '<<i<<'\n';
                    break;
                }
                if (lca(c, vl)!=vl) c=-1, idx=i+1;
                if (i==r) cout<<-1<<' '<<-1<<'\n';
            }
        }
    }
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44