Submission #861212

#	Time	Username	Problem	Language	Result	Execution time	Memory
861212		Trisanu_Das	Birthday gift (IZhO18_treearray)	C++17	56 / 100	4030 ms	22356 KiB

treearray

#include <bits/stdc++.h>
using namespace std;
 
int n, m, q, par[200005], g[200005] = {-1}, a[200005];
vector<int> adj[200005];
 
void dfs(int u, int p) {
	g[u] = g[p] + 1;
	par[u] = p;
	for(auto v : adj[u]) if(v != p) dfs(v, u);
}
 
int lca(int v, int u) {
	if(g[v] > g[u]) return lca(par[v], u);
	if(g[v] < g[u]) return lca(v, par[u]);
	if(v != u) return lca(par[v], u);
	return v;
}
 
int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);
	cin >> n >> m >> q;
	for (int i = 1; i < n; i++){
		int u, v; cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for (int i = 1; i < m + 1; i++) cin >> a[i];
	dfs(1, 0);
	while(q--){
		int op; cin >> op;
		if(op == 1){
			int idx, val; cin >> idx >> val;
          a[idx] = val;
		}
		else {
			int l, r, v, ptr_l = -1, ptr_r = -1; cin >> l >> r >> v;
			for (int u = l; u <= r; u++){
				if(u != r && lca(a[u], a[u + 1]) == v){
					ptr_l = u; ptr_r = u + 1;
					break;
                } else if(a[u] == v){
                    ptr_l = u; ptr_r = u;
					break;
				}
			}
			cout << ptr_l << ' ' << ptr_r << '\n';
		}
	}
}

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