Submission #503450

#	Time	Username	Problem	Language	Result	Execution time	Memory
503450		sumit_kk10	Birthday gift (IZhO18_treearray)	C++17	0 / 100	24 ms	28496 KiB

treearray

#include <bits/stdc++.h>
#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL)
#define ll long long int
#define ld long double
using namespace std;
const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
int n, m, q, lvl[N], tin[N], tout[N], timer;
vector<int> graph[N];
vector<vector<int> > dp(N, vector<int>(20, -1));
 
void dfs(int source, int par, int level){
	dp[source][0] = par;
	lvl[source] = level;
	tin[source] = ++timer;
	for(auto k : graph[source])
		if(k != par)
			dfs(k, source, level + 1);
	tout[source] = ++timer;
}
 
void init(){
	dfs(1, -1, 0);
	for(int i = 1; i <= (log2(n)); ++i)
		for(int j = 1; j <= n; ++j)
			if(dp[j][i - 1] != -1)
				dp[j][i] = dp[dp[j][i - 1]][i - 1];
}
 
ll LCA(int u, int v){
	if(lvl[u] > lvl[v]) swap(u, v);
	ll d = lvl[v] - lvl[u];
	while(d){
		int jump = log2(d);
		v = dp[v][jump];
		d -= pow(2, jump);
	}
	if(v == u) 
		return v;
	for(int i = log2(n); i >= 0; --i){
		if(dp[v][i] != -1 && dp[v][i] != dp[u][i]){
			u = dp[u][i];
			v = dp[v][i];
		}
	}
	return dp[v][0];
}
 
void solve(){
	cin >> n >> m >> q;
	vector<int> seq;
	for(int i = 0; i < n - 1; ++i){
		int u, v;
		cin >> u >> v;
		graph[u].push_back(v);
		graph[v].push_back(u);
	}
	for(int i = 0; i < m; ++i){
		int x;
		cin >> x;
		seq.push_back(x);
	}
	init();
	while(q--){
		int query;
		cin >> query;
		if(query == 1){
			int x, val;
			cin >> x >> val;
			--x;
			seq[x] = val;
		}
		else{
			int l, r, v;
			cin >> l >> r >> v;
			--l, --r;
			bool ok = 0;
			int cur = -1, pre = -1;
			for(int i = 0; i < seq.size(); ++i){
				int x = seq[i];
				if(tin[x] >= tin[v] and tout[x] <= tout[v]){
					if(cur == -1){ 
						cur = x;
						pre = i;
					}else cur = LCA(cur, x);
				}
				else{
					cur = -1;
					pre = -1;
				}
				if(cur == v){
					cout << pre + 1 << ' ' << i + 1 << '\n';
					ok = 1;
					break;
				}
			}
			if(!ok) cout << "-1 -1\n";
		}
	}
}
 
int main(){
	fast;
	int t = 1;
	// cin >> t;
	while(t--)
		solve();
	return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'void solve()':
treearray.cpp:79:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |    for(int i = 0; i < seq.size(); ++i){
      |                   ~~^~~~~~~~~~~~

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