Submission #167641

#	Time	Username	Problem	Language	Result	Execution time	Memory
167641		HungAnhGoldIBO2020	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1342 ms	73208 KiB

treearray

#include<bits/stdc++.h>
using namespace std;
const int N=2e5+1;
const int LOG=18;
set<pair<int,int> > lis[N];
vector<int> adj[N];
int level[N],ancestor[LOG][N],ar[N],lef,rig;
void dfs(int x,int p){
	for(int i=1;i<LOG;i++){
		ancestor[i][x]=ancestor[i-1][ancestor[i-1][x]];
	}
	for(auto i:adj[x]){
		if(i!=p){
			level[i]=level[x]+1;
			ancestor[0][i]=x;
			dfs(i,x);
		}
	}
}
int findd(int x,int k){
	while(k){
		int y=__lg(k);
		x=ancestor[y][x];
		k-=(1<<y);
	}
	return x;
}
int LCA(int x,int y){
	if(level[x]>level[y]){
		x=findd(x,level[x]-level[y]);
	}
	y=findd(y,level[y]-level[x]);
	if(x==y){
		return x;
	}
	for(int i=LOG-1;i>-1;i--){
	 	if(ancestor[i][x]!=ancestor[i][y]){
	 		x=ancestor[i][x],y=ancestor[i][y];
		}
	}
	return ancestor[0][x];
}
signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n,i,j,k,l,m,q;
	cin>>n>>m>>q;
	for(i=1;i<n;i++){
		cin>>j>>k;
		adj[j].push_back(k);
		adj[k].push_back(j);
	}
	dfs(1,1);
	for(i=1;i<=m;i++){
		cin>>ar[i];
		lis[ar[i]].insert({i,i});
		if(i>1){
			lis[LCA(ar[i-1],ar[i])].insert({i-1,i});
		}
	}
	for(i=1;i<=q;i++){
		cin>>j;
		if(j==1){
			cin>>k>>l;
			lis[ar[k]].erase({k,k});
			if(k>1){
				lis[LCA(ar[k-1],ar[k])].erase({k-1,k});
			}
			if(k<m){
				lis[LCA(ar[k],ar[k+1])].erase({k,k+1});
			}
			ar[k]=l;
			lis[ar[k]].insert({k,k});
			if(k>1){
				lis[LCA(ar[k-1],ar[k])].insert({k-1,k});
			}
			if(k<m){
				lis[LCA(ar[k],ar[k+1])].insert({k,k+1});
			}
		}
		else{
			cin>>j>>k>>l;
			auto ite=lis[l].lower_bound({j,0});
			if(ite==lis[l].end()){
				lef=rig=-1;
			}
			else{
				if(ite->second<=k){
					lef=ite->first;
					rig=ite->second;
				}
				else{
					lef=rig=-1;
				}
			}
			cout<<lef<<' '<<rig<<'\n';
		}
	}
}
/*
5 4 4
1 2
3 1
3 4
5 3
4 5 2 3
2 1 3 1
1 3 5
2 3 4 5
2 1 3 1
*/

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