oj.uz

답안 #575896

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
575896 2022-06-11T14:05:03 Z eecs Papričice (COCI20_papricice) C++17
110 / 110
 187 ms 43308 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 200010;
int n, ans = INT_MAX, sz[maxn], fa[maxn];
vector<int> G[maxn];
set<int> V[maxn];

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n;
    for (int i = 1, u, v; i < n; i++) {
        cin >> u >> v;
        G[u].push_back(v), G[v].push_back(u);
    }
    auto chk = [&](int a, int b) {
        int c = n - a - b;
        if (a && b && c) ans = min(ans, max({a, b, c}) - min({a, b, c}));
    };
    auto dfs = [&](auto self, int u) -> void {
        sz[u] = 1;
        for (int v : G[u]) if (v ^ fa[u]) {
            fa[v] = u, self(self, v), sz[u] += sz[v];
            vector<int> V1, V2;
            auto it = V[u].upper_bound(n / 3);
            if (it != V[u].end()) V1.push_back(*it);
            if (it != V[u].begin()) V1.push_back(*prev(it));
            it = V[v].upper_bound(n / 3);
            if (it != V[v].end()) V2.push_back(*it);
            if (it != V[v].begin()) V2.push_back(*prev(it));
            for (int x : V1) for (int y : V2) chk(x, y);
            if (V[u].size() < V[v].size()) swap(V[u], V[v]);
            for (int x : V[v]) V[u].insert(x);
        }
        V[u].insert(sz[u]);
        auto it = V[u].lower_bound(sz[u] / 2);
        chk(*it, sz[u] - *it);
        if (it != V[u].begin()) chk(*prev(it), sz[u] - *prev(it));
    };
    dfs(dfs, 1);
    cout << ans << "\n";
    return 0;
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 14420 KB Output is correct
2 Correct 9 ms 14420 KB Output is correct
3 Correct 7 ms 14420 KB Output is correct
4 Correct 7 ms 14420 KB Output is correct
5 Correct 8 ms 14440 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 14420 KB Output is correct
2 Correct 9 ms 14420 KB Output is correct
3 Correct 7 ms 14420 KB Output is correct
4 Correct 7 ms 14420 KB Output is correct
5 Correct 8 ms 14440 KB Output is correct
6 Correct 8 ms 14548 KB Output is correct
7 Correct 8 ms 14548 KB Output is correct
8 Correct 8 ms 14548 KB Output is correct
9 Correct 8 ms 14548 KB Output is correct
10 Correct 9 ms 14548 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 14420 KB Output is correct
2 Correct 9 ms 14420 KB Output is correct
3 Correct 7 ms 14420 KB Output is correct
4 Correct 7 ms 14420 KB Output is correct
5 Correct 8 ms 14440 KB Output is correct
6 Correct 8 ms 14548 KB Output is correct
7 Correct 8 ms 14548 KB Output is correct
8 Correct 8 ms 14548 KB Output is correct
9 Correct 8 ms 14548 KB Output is correct
10 Correct 9 ms 14548 KB Output is correct
11 Correct 187 ms 33488 KB Output is correct
12 Correct 186 ms 34236 KB Output is correct
13 Correct 153 ms 33356 KB Output is correct
14 Correct 178 ms 33752 KB Output is correct
15 Correct 184 ms 34236 KB Output is correct
16 Correct 143 ms 32488 KB Output is correct
17 Correct 159 ms 33460 KB Output is correct
18 Correct 154 ms 43308 KB Output is correct
19 Correct 168 ms 34384 KB Output is correct
20 Correct 173 ms 34212 KB Output is correct