Submission #1133361

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133361		why1	Birthday gift (IZhO18_treearray)	C++20	0 / 100	12 ms	23872 KiB

treearray

#include <bits/stdc++.h>
using namespace std;

#define ll unsigned long long
#define pb push_back
#define pii pair<int,int>
#define sz size()
#define all(v) v.begin(),v.end()
#define fi first
#define se second

const int N = 2e5;
const int mod = 998244353;
const int INF = 1e9;

const int di[]={1,-1,0,0};
const int dj[]={0,0,1,-1};

int n,m,q;
int a[N+1];
vector<int> g[N+1];
int tin[N+1],tout[N+1];
int up[N+1][20],timer=1;
set<int> st[N+1],sgl[N+1];

void dfs(int v,int pr){
	tin[v]=timer++;
	up[v][0]=pr;
	for(int i = 1; i < 20; i++){
		up[v][i]=up[up[v][i-1]][i-1];
	}
	for(auto i: g[v]){
		if(i!=pr)
			dfs(i,v);
	}
	tout[v]=timer++;
}

bool check(int a,int b){
	return tin[a]<=tin[b] && tout[b]<=tout[a];
}

int lca(int a,int b){
	if(check(a,b))
		return a;
	if(check(b,a))
		return b;
	for(int i = 19; i >= 0; i--){
		if(!check(up[a][i],b))
			a=up[a][i];
	}
	return up[a][0];
}

void solve() {
	cin>>n>>m>>q;
	for(int i = 1; i <= n-1; i++){
		int x,y;
		cin>>x>>y;
		g[x].pb(y);
		g[y].pb(x);
	}
	for(int i = 1; i <= m; i++){
		cin>>a[i];
	}
	dfs(1,1);
	for(int i = 1; i <= m-1; i++){
		int x=lca(a[i],a[i+1]);
		st[x].insert(i);
	}
	for(int i = 1; i <= m; i++){
		sgl[a[i]].insert(i);
	}
	while(q--){
		int type;
		cin>>type;
		if(type==1){
			int pos,v;
			cin>>pos>>v;
			sgl[a[pos]].erase(pos);
			st[lca(a[pos],a[pos+1])].erase(pos);
			st[lca(a[pos],a[pos-1])].erase(pos-1);
			a[pos]=v;
			sgl[a[pos]].insert(pos);
			st[lca(a[pos],a[pos+1])].insert(pos);
			st[lca(a[pos],a[pos-1])].insert(pos-1);
		}
		else{
			int l,r,v;
			cin>>l>>r>>v;
			if(l==r){
				if(a[l]==v)
					cout<<l<<" "<<r<<"\n";
				else
					cout<<"-1 -1\n";
				continue;
			}
			auto p=st[v].lower_bound(r-1);
			auto s=sgl[v].lower_bound(r);
			if(!st[v].empty()){
				if(p==st[v].end())
					p--;
				if(l<=(*p)){
					cout<<(*p)<<" "<<(*p)+1<<"\n";
					continue;
				}
			}
			if(!sgl[v].empty()){
				if(s==sgl[v].end())
					s--;
				if(l<=(*s)){
					cout<<(*s)<<" "<<(*s)<<"\n";
					continue;
				}
			}
			cout<<"-1 -1\n";
		}
	}
}

int main() {

	//freopen("cowrun.in","r",stdin);
	//freopen("cowrun.out","w",stdout);

    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t=1;
	//cin>>t;
	while(t--) {
        solve();
	}	

    return 0;
}

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