Submission #345723

#	Time	Username	Problem	Language	Result	Execution time	Memory
345723		nandonathaniel	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1398 ms	81388 KiB

treearray

#include<bits/stdc++.h>
using namespace std;
const int MAXN=200005,LOG=18;

vector<int> adj[MAXN];
int depth[MAXN],pa[LOG][MAXN],a[MAXN];
set<int> sendiri[MAXN],berdua[MAXN];

void dfs(int now,int par){
	for(auto nxt : adj[now]){
		if(nxt==par)continue;
		depth[nxt]=depth[now]+1;
		pa[0][nxt]=now;
		for(int i=1;i<LOG;i++)pa[i][nxt]=pa[i-1][pa[i-1][nxt]];
		dfs(nxt,now);
	}
}

int LCA(int u,int v){
	if(depth[u]<depth[v])swap(u,v);
	int diff=depth[u]-depth[v];
	for(int i=LOG-1;i>=0;i--){
		if(diff&(1<<i))u=pa[i][u];
	}
	if(u==v)return u;
	for(int i=LOG-1;i>=0;i--){
		if(pa[i][u]!=pa[i][v]){
			u=pa[i][u];
			v=pa[i][v];
		}
	}
	return pa[0][u];
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	int n,m,q,op,x,y,u,v;
	cin >> n >> m >> q;
	for(int i=1;i<n;i++){
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	dfs(1,-1);
	for(int i=1;i<=m;i++){
		cin >> a[i];
		sendiri[a[i]].insert(i);
		if(i>=2){
			berdua[LCA(a[i-1],a[i])].insert(i-1);
		}
	}
	while(q--){
		cin >> op >> x >> y;
		if(op==1){
			sendiri[a[x]].erase(x);
			if(x>=2)berdua[LCA(a[x],a[x-1])].erase(x-1);
			if(x<=m-1)berdua[LCA(a[x],a[x+1])].erase(x);
			a[x]=y;
			sendiri[a[x]].insert(x);
			if(x>=2)berdua[LCA(a[x],a[x-1])].insert(x-1);
			if(x<=m-1)berdua[LCA(a[x],a[x+1])].insert(x);
		}
		else{
			cin >> v;
			bool sudah=false;
			auto it=sendiri[v].lower_bound(x);
			auto it2=berdua[v].lower_bound(x);
			if(it!=sendiri[v].end() && *it<=y){
				cout << *it << " " << *it << '\n';
			}
			else if(it2!=berdua[v].end() && *it2<=y-1){
				cout << *it2 << " " << (*it2)+1 << '\n';
			}
			else{
				cout << -1 << " " << -1 << '\n';
			}
		}
	}
	return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:65:9: warning: unused variable 'sudah' [-Wunused-variable]
   65 |    bool sudah=false;
      |         ^~~~~

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