oj.uz

답안 #487055

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
487055 2021-11-14T01:17:22 Z inksamurai Papričice (COCI20_papricice) C++17
110 / 110
 281 ms 27128 KB 
#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
#define rep(i,n) for(int i=0;i<n;i++)
#define crep(i,x,n) for(int i=x;i<n;i++)
#define drep(i,n) for(int i=n-1;i>=0;i--)
#define vec(...) vector<__VA_ARGS__>
#define _322ZVFH ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
using pii=pair<int,int>;
using vi=vector<int>;
 
int main(){
_322ZVFH;
	int n;
	cin>>n;
	vec(vi) adj(n);
	rep(i,n-1){
		int u,v;
		cin>>u>>v;
		u--,v--;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	vi chs(n,0);
	auto dfs=[&](auto self,int v,int par)->void{
		chs[v]=1;
		for(auto u : adj[v]){
			if(u!=par){
				self(self,u,v);
				chs[v]+=chs[u];
			}
		}
	};
	dfs(dfs,0,-1);
	multiset<int> up,lo;
	int ans=1e9;
	auto g=[&](int _a,int _b,int _c){
		ans=min(ans,max({_a,_b,_c})-min({_a,_b,_c}));
	};
	auto f=[&](int v){
		int l=chs[v];
		vi rbts={(n+l)/2,(n-l)/2};
		rep(i,2){
			int rabbit=rbts[i];
			auto it=(i==0?up.lower_bound(rabbit):lo.lower_bound(rabbit));
			auto it1=(i==0?up.lower_bound(rabbit):lo.lower_bound(rabbit));
			auto it2=(i==0?up.lower_bound(rabbit):lo.lower_bound(rabbit));
			vi candies;
			if((i==0?it!=up.end():it!=lo.end())){
				candies.pb(*it);
			}
			if((i==0?it1!=up.end():it1!=lo.end())){
				it1=next(it1);
				candies.pb(*it1);
			}
			if((i==0?it2!=up.begin():it2!=lo.begin())){
				it2=prev(it2);
				candies.pb(*it2);
			}
			for(auto x : candies){
				if(x==chs[0]) continue;
				if(i==0) g(x-l,l,n-x);
				else g(x,l,n-x-l);
			}
		}
	};
	auto dfs1=[&](auto self,int v,int par)->void{
		f(v);
		up.insert(chs[v]);
		for(auto u : adj[v]){
			if(u!=par){
				self(self,u,v);
			}
		}
		lo.insert(chs[v]);
		up.erase(up.find(chs[v]));
	};
	dfs1(dfs1,0,-1);
	cout<<ans<<"\n";
//	
	return 0;
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 216 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 216 KB Output is correct
6 Correct 2 ms 460 KB Output is correct
7 Correct 2 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 2 ms 460 KB Output is correct
10 Correct 2 ms 460 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 216 KB Output is correct
6 Correct 2 ms 460 KB Output is correct
7 Correct 2 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 2 ms 460 KB Output is correct
10 Correct 2 ms 460 KB Output is correct
11 Correct 244 ms 21564 KB Output is correct
12 Correct 281 ms 23972 KB Output is correct
13 Correct 211 ms 24388 KB Output is correct
14 Correct 216 ms 24168 KB Output is correct
15 Correct 254 ms 23964 KB Output is correct
16 Correct 187 ms 23976 KB Output is correct
17 Correct 233 ms 24104 KB Output is correct
18 Correct 252 ms 27128 KB Output is correct
19 Correct 222 ms 24132 KB Output is correct
20 Correct 244 ms 23960 KB Output is correct