Submission #752327

#	Time	Username	Problem	Language	Result	Execution time	Memory
752327		iulia13	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1549 ms	87068 KiB

treearray

#include <bits/stdc++.h>

using namespace std;
const int N = 2e5 + 5;
const int LG = 20;
vector <int> g[N];
set <int> L[N];
set <int> V[N];
int dad[N][LG];
int lvl[N], a[N], n;
void dfs(int nod)
{
    for (auto x : g[nod])
    {
        if (x == dad[nod][0])
            continue;
        dad[x][0] = nod;
        lvl[x] = lvl[nod] + 1;
        dfs(x);
    }
}
void lifting()
{
    for (int j = 1; j < LG; j++)
        for (int i = 1; i <= n; i++)
            dad[i][j] = dad[dad[i][j - 1]][j - 1];
}
int lca(int x, int y)
{
    if (lvl[x] < lvl[y])
        swap(x, y);
    int lg = LG - 1;
    while (lvl[x] > lvl[y] && lg != -1)
    {
        if (lvl[dad[x][lg]] >= lvl[y])
            x = dad[x][lg];
        lg--;
    }
    lg = LG - 1;
    while (x != y && lg != -1)
    {
        if (dad[x][lg] != dad[y][lg])
        {
            x = dad[x][lg];
            y = dad[y][lg];
        }
        lg--;
    }
    if (x == y)
        return x;
    return dad[x][0];
}
int main()
{
    int m, q;
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++)
    {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    dfs(1);
    lifting();
    for (int i = 1; i <= m; i++)
    {
        cin >> a[i];
        V[a[i]].insert(i);
        if (1 < i)
            L[lca(a[i], a[i - 1])].insert(i);
    }
    while(q--)
    {
        int tip;
        cin >> tip;
        if (tip == 1)
        {
            int pos, v;
            cin >> pos >> v;
            V[a[pos]].erase(pos);
            V[v].insert(pos);
            if (pos != 1)
            {
                L[lca(a[pos], a[pos - 1])].erase(pos);
                L[lca(v, a[pos - 1])].insert(pos);
            }
            if (pos != m)
            {
                L[lca(a[pos], a[pos + 1])].erase(pos + 1);
                L[lca(v, a[pos + 1])].insert(pos + 1);
            }
            a[pos] = v;
            continue;
        }
        int l, r,val;
        cin >> l >> r >> val;
        auto it = V[val].lower_bound(l);
        if (it != V[val].end())
        {
            int ll = *it;
            if (ll <= r)
            {
                cout << ll << " " << ll << '\n';
                continue;
            }
        }
        it = L[val].lower_bound(l + 1);
        if (it != L[val].end())
        {
            int lll = *it;
            if (lll <= r)
                cout << lll - 1 << " " << lll;
            else
                cout << -1 << " " << -1;
            cout << '\n';
            continue;
        }
        cout << -1 << " " << -1;
            cout << '\n';
    }
    return 0;
}

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