oj.uz

답안 #677331

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
677331 2023-01-02T21:13:21 Z rafatoa Papričice (COCI20_papricice) C++17
110 / 110
 226 ms 27696 KB 
#include <bits/stdc++.h>
using namespace std;

#define F first
#define S second
#define int long long
const int INF = 1e18;

void solve(){
    int n; cin >> n;
    vector<vector<int>> adj(n+1);

    for(int i=0; i<n-1; i++){
        int u, v; cin >> u >> v;
        adj[u].push_back(v); adj[v].push_back(u);
    }

    vector<int> sub(n+1);
    map<int, int> a, b;
    function<void(int, int)> dfs0 = [&](int s, int e){
        sub[s] = 1;
        for(auto &u:adj[s]){
            if(u == e) continue;
            dfs0(u, s);
            sub[s] += sub[u];
        }
    };
    dfs0(1, 0);

    int ans = INF;
    function<void(int, int)> dfs = [&](int s, int e){
        auto it1 = a.lower_bound((n+sub[s])/2);
        auto it2 = b.lower_bound((n-sub[s])/2);

        if(!a.empty()){
            if(it1 != a.end()) ans = min(ans, max({sub[s], it1->F-sub[s], n-it1->F}) - min({sub[s], it1->F-sub[s], n-it1->F}));
            if(it1 != a.begin()) it1--, ans = min(ans, max({sub[s], it1->F-sub[s], n-it1->F}) - min({sub[s], it1->F-sub[s], n-it1->F}));
        }
        if(!b.empty()){
            if(it2 != b.end()) ans = min(ans, max({sub[s], it2->F, n-it2->F-sub[s]}) - min({sub[s], it2->F, n-it2->F-sub[s]}));
            if(!b.empty() && it2 != b.begin()) it2--, ans = min(ans, max({sub[s], it2->F, n-it2->F-sub[s]}) - min({sub[s], it2->F, n-it2->F-sub[s]}));
        }

        a[sub[s]]++;
        for(auto &u:adj[s]){
            if(u == e) continue;
            dfs(u, s);
        }
        a[sub[s]]--;
        if(a[sub[s]] == 0) a.erase(sub[s]);
        b[sub[s]]++;
    };
    dfs(1, 0);
    cout << ans << "\n";
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    solve();
    return 0;
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 324 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 324 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 2 ms 468 KB Output is correct
7 Correct 2 ms 460 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 324 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 2 ms 468 KB Output is correct
7 Correct 2 ms 460 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 218 ms 16504 KB Output is correct
12 Correct 226 ms 16568 KB Output is correct
13 Correct 159 ms 17096 KB Output is correct
14 Correct 166 ms 16732 KB Output is correct
15 Correct 194 ms 16460 KB Output is correct
16 Correct 108 ms 16176 KB Output is correct
17 Correct 163 ms 16612 KB Output is correct
18 Correct 193 ms 27696 KB Output is correct
19 Correct 158 ms 16756 KB Output is correct
20 Correct 171 ms 16564 KB Output is correct