Submission #492871

#	Time	Username	Problem	Language	Result	Execution time	Memory
492871		duchung	Birthday gift (IZhO18_treearray)	C++17	100 / 100	1231 ms	90396 KiB

treearray

#include<bits/stdc++.h>
using namespace std;

const int N = 2e5 + 5;

int n , m , q;
vector<int> edge[N];
int depth[N];
int up[N][20];
int a[N];
set<int> pos[N][2];

void dfs(int u , int p = -1)
{
	for (int v : edge[u])
	{
		if (v == p) continue;
		
		up[v][0] = u;
		for (int j = 1 ; j < 20 ; ++j) up[v][j] = up[up[v][j - 1]][j - 1];

		depth[v] = depth[u] + 1;
		dfs(v , u);
	}
}

int lca(int u , int v)
{
	if (u == v) return u;
	if (depth[u] < depth[v]) swap(u , v);

	for (int j = 19 ; j >= 0 ; --j)
	{
		if (depth[u] - (1 << j) >= depth[v])
		{
			u = up[u][j];
		}
	}

	if (u == v) return u;

	for (int j = 19 ; j >= 0 ; --j)
	{
		if (up[u][j] != up[v][j])
		{
			u = up[u][j];
			v = up[v][j];
		}
	}

	return up[u][0];
}

int main()
{
	// freopen("input.inp","r",stdin);
	// freopen("output.out","w",stdout);
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	cin >> n >> m >> q;
	for (int i = 1 ; i < n ; ++i)
	{
		int u , v;
		cin >> u >> v;
		edge[u].push_back(v);
		edge[v].push_back(u);
	}

	dfs(1);

	for (int i = 1 ; i <= m ; ++i) cin >> a[i];
	for (int i = 1 ; i <= m ; ++i) pos[a[i]][0].insert(i);
	for (int i = 1 ; i < m ; ++i) pos[lca(a[i] , a[i + 1])][1].insert(i);

	while(q--)
	{
		int opt;
		cin >> opt;
		if (opt == 1)
		{
			int p , v;
			cin >> p >> v;

			if (p + 1 <= m)
			{
				pos[lca(a[p] , a[p + 1])][1].erase(p);
				pos[lca(v , a[p + 1])][1].insert(p);
			}

			if (p >= 2)
			{
				pos[lca(a[p] , a[p - 1])][1].erase(p - 1);
				pos[lca(v , a[p - 1])][1].insert(p - 1);
			}

			pos[a[p]][0].erase(p);
			pos[v][0].insert(p);

			a[p] = v;
		}
		else
		{
			int l , r , v;
			cin >> l >> r >> v;

			auto single_node = pos[v][0].lower_bound(l);
			auto double_node = pos[v][1].lower_bound(l);

			if (single_node != pos[v][0].end() && *single_node <= r) cout << *single_node << " " << *single_node << "\n";
			else if (double_node != pos[v][1].end() && *double_node + 1 <= r) cout << *double_node << " " << *double_node + 1 << "\n";
			else cout << "-1 -1\n";
		}
	}

}

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