Submission #651193

#	Time	Username	Problem	Language	Result	Execution time	Memory
651193		pcc	Birthday gift (IZhO18_treearray)	C++14	12 / 100	4 ms	348 KiB

treearray

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

#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define io ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ld long double
#define _all(T) T.begin(),T.end()
const int mxn = 1e3+10;

vector<int> paths[mxn];
int fa[mxn],link_top[mxn],bs[mxn],sz[mxn],dep[mxn],arr[mxn];

void dfs1(int now,int par){
	fa[now] = par;
	sz[now] = 1;
	for(auto nxt:paths[now]){
		if(nxt == par)continue;
		dep[nxt] = dep[now]+1;
		dfs1(nxt,now);
		if(bs[now] == 0||sz[bs[now]] < sz[nxt])bs[now] = nxt;
		sz[now] += sz[nxt];
	}
	return;
}
void dfs2(int now,int top){
	link_top[now] = top;
	if(bs[now])dfs2(bs[now],top);
	for(auto nxt:paths[now]){
		if(nxt == fa[now]||nxt == bs[now])continue;
		dfs2(nxt,nxt);
	}
	return;
}
int lca(int a,int b){
	int ta = link_top[a],tb = link_top[b];
	while(ta != tb){
		if(dep[ta]<dep[tb]){
			swap(ta,tb);
			swap(a,b);
		}
		a = fa[ta];
		ta = link_top[a];
	}
	if(dep[a]>dep[b])return b;
	else return a;
}
int main(){
	io
	int n,m,q;
	cin>>n>>m>>q;
	if(m*m*q*__lg(n)>=1e9)return 0;
	for(int i = 0;i<n-1;i++){
		int a,b;
		cin>>a>>b;
		paths[a].push_back(b);
		paths[b].push_back(a);
	}
	dfs1(1,1);
	dfs2(1,1);
	for(int i = 1;i<=m;i++){
		cin>>arr[i];
	}
//	cout<<lca(3,4);
	while(q--){
		int t;
		cin>>t;
		if(t == 1){
			int p,v;
			cin>>p>>v;
			arr[p] = v;
		}
		else{
			int l,r,v;
			cin>>l>>r>>v;
			pii ans = {-1,-1};
			for(int i = l;i<=r;i++){
				int now = arr[i];
				for(int j= i;j<=r;j++){
					now = lca(now,arr[j]);
					if(now == v){
						ans = {i,j};
					}
				}
			}
			cout<<ans.fs<<' '<<ans.sc<<'\n';
		}
	}
	return 0;
}
/*
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: 0 / 18
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44