Submission #167664

#	Time	Username	Problem	Language	Result	Execution time	Memory
167664		shuvi_dola	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1513 ms	81964 KiB

treearray

#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
vector <int> g[N];
int a[N], dep[N], par[N][23];
set <int> posver[N], poslca[N];
int n, m, q;
void dfs(int s, int p) {
	par[s][0] = p;
	for(int i = 1; i <= 20; i++) {
		par[s][i] = par[par[s][i - 1]][i - 1];
	}
	for(auto u : g[s]) {
		if(u == p) continue;
		dep[u] = dep[s] + 1;
		dfs(u, s);
	}
}

int lca(int u, int v) {
	if(dep[u] < dep[v]) swap(u, v);
	for(int i = 20; i >= 0; i--) if(dep[u] - dep[v] >= (1 << i)) u = par[u][i];
	if(u == v) return u;
	for(int i = 20; i >= 0; i--)  if(par[u][i] != par[v][i]) u = par[u][i], v = par[v][i]; 
	return par[u][0];
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> n >> m >> q;
	for(int i = 1; i < n; i++) {
		int u, v;
		cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}

	dfs(1, 0);
	for(int i = 1; i <= m; i++) {
		cin >> a[i];
		posver[a[i]].insert(i);
		if(i > 1) poslca[lca(a[i], a[i - 1])].insert(i);
	}

	while(q--) {
		int typ, x, y ,ver;
		cin >> typ >> x >> y;
		if(typ == 1) {
			posver[a[x]].erase(x);
			if(x > 1) poslca[lca(a[x], a[x - 1])].erase(x);
			if(x < m) poslca[lca(a[x], a[x + 1])].erase(x + 1);
			a[x] = y;
			posver[a[x]].insert(x);
			if(x > 1) poslca[lca(a[x], a[x - 1])].insert(x);
			if(x < m) poslca[lca(a[x], a[x + 1])].insert(x + 1);
		}

		else {
			cin >> ver;
			if(posver[ver].size() > 0) {
				auto L = posver[ver].lower_bound(x);
				if(L != posver[ver].end() && *L <= y) {
					cout << *L << ' ' << *L << '\n';
					continue; 
				}
			}
			if(poslca[ver].size() > 0) {
				auto L = poslca[ver].lower_bound(x + 1);
				if(L != poslca[ver].end() && *L <= y) {
					cout << (*L) - 1 << ' ' << *L << '\n';
					continue;
				}
			}
			cout << "-1 -1 \n";
		}
	}
}

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