Submission #1248378

#	Time	Username	Problem	Language	Result	Execution time	Memory
1248378		dfhdfhdsf	Papričice (COCI20_papricice)	C++20	110 / 110	141 ms	21044 KiB

papricice

#include <iostream>
#include<bits/stdc++.h>
using namespace std;
#define task "coci2021_r1_papricice"
const int N = 2e5 + 5 ; 
int n ; 
vector<int> D[N] ;  
void Inp()
{
    cin >> n ; 
    for(int i = 1 ; i < n ; i++){
        int u , v ;
        cin >> u>> v; 
        D[u].push_back(v) ;
        D[v].push_back(u) ; 
    }
}
namespace SUB2{
    set<int> A , B ; 
    int cnt[N] ;
    void dfs(int u , int p){
        cnt[u] = 1 ; 
        for(int v : D[u]){
            if(v == p) continue; 
            dfs(v , u) ; 
            cnt[u] += cnt[v] ; 
        }
    } 
    int get_dif(int a , int b , int c){
           return max({a , b , c}) - min({a , b , c}) ;  
    }
    vector<int> get_result(const set<int>&A , int x){
        vector<int> res ; 
        auto j = A.upper_bound(x) ; 
        if(j != A.end()) res.push_back(*j) ; 
        if(j != A.begin()) {
            --j ; 
            res.push_back(*j) ; 
        }
        return res ; 
    }
    int dfs2(int u , int p){
        int res = 1e9 ; 
        for(auto x : get_result(A , (n + cnt[u]) / 2)){
            res = min(res , get_dif(n - x , cnt[u], x - cnt[u])) ; 
        }
        for(auto x : get_result(B , (n - cnt[u]) / 2)){
            res = min(res , get_dif(n - x - cnt[u] , x , cnt[u])) ; 
        }
        A.insert(cnt[u]) ; 
        for(int v : D[u]){
            if(v == p) continue; 
            res = min(res , dfs2(v , u)) ;     
        }
        A.erase(cnt[u]) ; 
        B.insert(cnt[u]) ; 
        return res ; 
    }
    void Solve(){
        dfs(1 , 0) ; 
        cout << dfs2(1 , 0) ; 
    }
}
void Solve()
{
    SUB2::Solve() ; 

}
void Out() 
{
    
}
int main()
{
    ios_base::sync_with_stdio(NULL);cin.tie(NULL);cout.tie(NULL);
    if(ifstream(task".INP")){
        freopen(task".INP","r",stdin) ; 
        freopen(task".OUT","w",stdout) ;
    }
    Inp();
    Solve();
    Out(); 
    return 0;
}

Compilation message (stderr)

papricice.cpp: In function 'int main()':
papricice.cpp:77:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |         freopen(task".INP","r",stdin) ;
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
papricice.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |         freopen(task".OUT","w",stdout) ;
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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