oj.uz

답안 #376315

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
376315 2021-03-11T08:19:03 Z errorgorn Papričice (COCI20_papricice) C++17
50 / 110
 1000 ms 286656 KB 
//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define up upper_bound

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

int n;
vector<int> al[200005];
set<int> s[200005];
int sz[200005];

void dfs_sz(int i,int p){
	sz[i]=1;
	
	for (auto &it:al[i]){
		if (it==p) continue;
		dfs_sz(it,i);
		sz[i]+=sz[it];
	}
}

ll ans=1e9;

ll calc(int i,int j){
	int k=n-i-j;
	int arr[3]={i,j,k};
	sort(arr,arr+3);
	return arr[2]-arr[0];
}

void dfs(int i,int p){
	for (auto &it:al[i]){
		if (it==p) continue;
		
		dfs(it,i);
		
		if (s[it]>s[i]) swap(s[it],s[i]);
		
		for (auto &it:s[it]){
			auto temp=s[i].lb((n-it)/2);
			if (temp!=s[i].begin()){
				ans=min(ans,calc(it,*prev(temp)));
			}
			if (temp!=s[i].end()){
				ans=min(ans,calc(it,*temp));
			}
		}
		
		for (auto &it:s[it]) s[i].insert(it);
		
		// auto temp=s[i];
		// for (auto &it:s[it]){
			// s[i].insert(it);
			// for (auto &it2:temp) ans=min(ans,calc(it,it2));
		// }
	}
	
	auto temp=s[i].lb(sz[i]/2);
	if (temp!=s[i].begin()){
		ans=min(ans,calc(sz[i]-*prev(temp),*prev(temp)));
	}
	if (temp!=s[i].end()){
		ans=min(ans,calc(sz[i]-*temp,*temp));
	}
	
	//for (auto &it:s[i]) ans=min(ans,calc(sz[i]-it,it));
	
	s[i].insert(sz[i]);
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	cin>>n;
	
	int a,b;
	rep(x,1,n){
		cin>>a>>b;
		al[a].pub(b);
		al[b].pub(a);
	}
	
	dfs_sz(1,-1);
	dfs(1,-1);
	
	cout<<ans<<endl;
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 14444 KB Output is correct
2 Correct 10 ms 14444 KB Output is correct
3 Correct 10 ms 14444 KB Output is correct
4 Correct 10 ms 14444 KB Output is correct
5 Correct 10 ms 14444 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 14444 KB Output is correct
2 Correct 10 ms 14444 KB Output is correct
3 Correct 10 ms 14444 KB Output is correct
4 Correct 10 ms 14444 KB Output is correct
5 Correct 10 ms 14444 KB Output is correct
6 Correct 11 ms 14700 KB Output is correct
7 Correct 14 ms 14700 KB Output is correct
8 Correct 12 ms 14700 KB Output is correct
9 Correct 12 ms 14700 KB Output is correct
10 Correct 14 ms 14700 KB Output is correct

Subtask #3
0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 14444 KB Output is correct
2 Correct 10 ms 14444 KB Output is correct
3 Correct 10 ms 14444 KB Output is correct
4 Correct 10 ms 14444 KB Output is correct
5 Correct 10 ms 14444 KB Output is correct
6 Correct 11 ms 14700 KB Output is correct
7 Correct 14 ms 14700 KB Output is correct
8 Correct 12 ms 14700 KB Output is correct
9 Correct 12 ms 14700 KB Output is correct
10 Correct 14 ms 14700 KB Output is correct
11 Correct 366 ms 41532 KB Output is correct
12 Correct 348 ms 47596 KB Output is correct
13 Correct 264 ms 40812 KB Output is correct
14 Correct 285 ms 40604 KB Output is correct
15 Correct 316 ms 39892 KB Output is correct
16 Correct 201 ms 31720 KB Output is correct
17 Correct 288 ms 42604 KB Output is correct
18 Execution timed out 1114 ms 286656 KB Time limit exceeded
19 Halted 0 ms 0 KB -