Submission #167514

#	Time	Username	Problem	Language	Result	Execution time	Memory
167514		manh9203	Birthday gift (IZhO18_treearray)	C++17	100 / 100	1341 ms	84296 KiB

treearray

#include<bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
int n,m,q,u,v,a[N],par[N][20],h[N],type,l,r,id;
vector<int> adj[N];
set<int> pos1[N],pos2[N];
void dfs(int u,int p){
	for(int v: adj[u]){
		if(v != p){
			h[v] = h[u] + 1;
			par[v][0] = u;
			dfs(v, u);
		}
	}
}
int lca(int u,int v){
	if(h[u] < h[v]) swap(u, v);
	for(int i=18;i>=0;i--){
		if(h[u] - (1<<i) >= h[v]){
			u = par[u][i];
		}
	}
	if(u == v){
		return u;
	}else{
		for(int i=18;i>=0;i--){
			if(par[u][i] != -1 && par[v][i] != -1 && 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(0); cin.tie(0); cout.tie(0);
	cin >> n >> m >> q;
	for(int i=1;i<n;i++){
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	h[1] = 1;
	memset(par, -1, sizeof par);
	dfs(1, 1);
	for(int j=1;(1<<j)<=n;j++){
		for(int i=1;i<=n;i++){
			if(par[i][j-1] != -1){
				par[i][j] = par[par[i][j-1]][j-1];
			}
		}
	}
	for(int i=1;i<=m;i++){
		cin >> a[i];
		pos1[a[i]].insert(i);
	}
	for(int i=1;i<m;i++){
		u = lca(a[i], a[i+1]);
		pos2[u].insert(i);
	}
	while(q--){
		cin >> type;
		if(type == 1){
			cin >> id >> v;
			pos1[a[id]].erase(id);
			if(id > 1){
				u = lca(a[id-1], a[id]);
				pos2[u].erase(id-1);
			}
			if(id < m){
				u = lca(a[id], a[id+1]);
				pos2[u].erase(id);
			}
			a[id] = v;
			pos1[a[id]].insert(id);
			if(id > 1){
				u = lca(a[id-1], a[id]);
				pos2[u].insert(id-1);
			}
			if(id < m){
				u = lca(a[id], a[id+1]);
				pos2[u].insert(id);
			}
		}
		if(type == 2){
			cin >> l >> r >> v;
			if(pos1[v].size() > 0){
				auto it = pos1[v].lower_bound(l);
				if(it != pos1[v].end() && *it <= r){
					cout << *it << " " << *it << "\n";
					continue;
				}
			}
			if(pos2[v].size() > 0){
				auto it1 = pos2[v].lower_bound(l);
				if(it1 != pos2[v].end() && *it1 < r){
					cout << *it1 << " " << (*it1) + 1 << "\n";
					continue;
				}
			}
			cout << "-1 -1\n";
		}
	}
}

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