oj.uz

답안 #766646

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
766646 2023-06-26T03:29:18 Z Pichon5 Papričice (COCI20_papricice) C++17
0 / 110
 4 ms 5076 KB 
#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
#include <string>
#include <sstream>
#include <fstream>
#include <cmath>
#include <queue>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#define lcm(a,b) (a/__gcd(a,b))*b
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ll long long int
#define vi vector<int>
#define vll vector<ll>
#define pb push_back
#define F first
#define S second
#define mp make_pair
using namespace std;
const int tam=200005;
vi G[tam];
int sz[tam];
multiset<int> todos,down;
int res=1e9;
void init(int nodo, int ant){
    sz[nodo]=1;
    for(auto x:G[nodo]){
        if(x!=ant){
            init(x,nodo);
            sz[nodo]+=sz[x];
        }
    }
}
int n;

//haré un small to large
void dfs(int nodo, int ant){
    
    //primero quiero probar con los de arriba
    int grupo1=sz[nodo];
    //n-it2, it2-grupo1, grupo1
    //quiero elegir el mejor it2 de don tal que, n-it2 sea los mas cercano a it2-grupo1
    auto it2=down.lower_bound((n+grupo1)/2);
    if(it2!=down.end()){
        int val=(*it2);
        
        vi A;
        A.pb(val-grupo1);A.pb(grupo1);A.pb(n-val);
        sort(A.begin(),A.end());
        res=min(res,A[2]-A[0]);
    }
    it2=down.begin();
    if(it2!=down.end()){
        int val=(*it2);
        vi A;
        A.pb(val-grupo1);A.pb(grupo1);A.pb(n-val);
        sort(A.begin(),A.end());
        res=min(res,A[2]-A[0]);
    }

    if(ant!=-1){
        down.insert(sz[nodo]);
    }
    //dfs
    // cout<<"nodardo  "<<nodo<<endl;
    for(auto it : G[nodo]){
        if(it==ant)continue;
        int tami=sz[it];
        int falta=n-tami;
        auto it2=todos.lower_bound(falta/2);
        // if(it==5){
        //     cout<<"val "<<todos.size()<<endl;
        //         for(auto x:todos){
        //             cout<<x<<" ";
        //         }
        //     cout<<endl;
        // }
        if(it2!=todos.end()){
            
            int val=(*it2);
            vi A;
            A.pb(val);A.pb(falta-val);A.pb(tami);
            sort(A.begin(),A.end());
            res=min(res,A[2]-A[0]);
        }
        it2=todos.begin();
        if(it2!=todos.end()){
            int val=(*it2);
            vi A;
            A.pb(val);A.pb(falta-val);A.pb(tami);
            sort(A.begin(),A.end());
            res=min(res,A[2]-A[0]);
        }

        dfs(it,nodo);
    }
    // cout<<"nodo "<<nodo<<endl;
    if(ant!=-1){
        //ya puedo meter
        // cout<<"metiendo "<<sz[nodo]<<endl;
        todos.insert(sz[nodo]);
        down.erase(down.find(sz[nodo]));
    }
}
int main(){
    int a,b;
    cin>>n;
    for(int i=1;i<n;i++){
        cin>>a>>b;
        G[a].pb(b);
        G[b].pb(a);
    }
    init(1,-1);
    dfs(1,-1);
    cout<<res<<endl;

    return 0;
}

Subtask #1
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5076 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Incorrect 3 ms 4944 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5076 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Incorrect 3 ms 4944 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #3
0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5076 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Incorrect 3 ms 4944 KB Output isn't correct
4 Halted 0 ms 0 KB -