Submission #732951

#	Time	Username	Problem	Language	Result	Execution time	Memory
732951		Koful123	Papričice (COCI20_papricice)	C++17	0 / 110	7 ms	16024 KiB

papricice

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define ff first
#define ss second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
 
const int N = 2e5 + 5;
int ans = 1e18,n; multiset<int> s[N];
vector<int> adj[N],sz(N);
 
void merge(multiset<int> &a,multiset<int> &b){
	if(a.size() < b.size()) swap(a,b);
	for(int x : b){
		a.insert(x);
	}
}
 
void dfs(int node,int p){
	sz[node] = 1;
	for(int go : adj[node]){
		if(go == p) continue;
		dfs(go,node);
		sz[node] += sz[go];
		merge(s[node],s[go]);
	}
	s[node].insert(sz[node]);
	auto f = s[node].upper_bound(sz[node] / 2);
	if(f != s[node].end()){
		vector<int> tmp = {*f,sz[node] - *f,n - sz[node]};
		sort(tmp.begin(),tmp.end());
		ans = min(ans,tmp[2] - tmp[0]);
	}
	if(f != s[node].begin()){
		auto s = prev(f);
		vector<int> tmp = {*s,sz[node] - *s,n - sz[node]};
		sort(tmp.begin(),tmp.end());
		ans = min(ans,tmp[2] - tmp[0]);	
	}
}

void calc(int node,int p){
	s[1].erase(sz[node]);
	for(int go : adj[node]){
		if(go == p) continue;
		dfs(go,node);
	}
	auto f = s[1].upper_bound((n - sz[node]) / 2);
	if(f != s[1].end()){
		vector<int> tmp = {sz[node],*f,n - sz[node] - *f};
		sort(tmp.begin(),tmp.end());
		ans = min(ans,tmp[2] - tmp[0]);
	}
	if(f != s[1].begin()){
		auto s = prev(f);
		vector<int> tmp = {*s,sz[node],n - sz[node] - *s};
		sort(tmp.begin(),tmp.end());
		ans = min(ans,tmp[2] - tmp[0]);	
	}
	s[1].insert(sz[node]);
}
 
void solve(){
 
	cin >> n;
	for(int i = 1; i < n; i++){
		int a,b; cin >> a >> b;
		adj[a].push_back(b);
		adj[b].push_back(a);
	}


	dfs(1,0);  calc(1,0);
	cout << ans << endl;
}
 
signed main(){ 
 
	ios::sync_with_stdio(0);
	cin.tie(0);
 
	int t = 1;
//	cin >> t;
 
	while(t--)
		solve();
 	
	return 0;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 35
• Subtask 3: 0 / 60