oj.uz

답안 #575895

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
575895 2022-06-11T14:04:05 Z eecs Papričice (COCI20_papricice) C++17
110 / 110
 204 ms 43340 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].lower_bound((n + 2) / 3);
            if (it != V[u].end()) V1.push_back(*it);
            if (it != V[u].begin()) V1.push_back(*prev(it));
            it = V[v].lower_bound((n + 2) / 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 14428 KB Output is correct
2 Correct 7 ms 14420 KB Output is correct
3 Correct 7 ms 14336 KB Output is correct
4 Correct 7 ms 14432 KB Output is correct
5 Correct 7 ms 14420 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 14428 KB Output is correct
2 Correct 7 ms 14420 KB Output is correct
3 Correct 7 ms 14336 KB Output is correct
4 Correct 7 ms 14432 KB Output is correct
5 Correct 7 ms 14420 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 14600 KB Output is correct
9 Correct 9 ms 14548 KB Output is correct
10 Correct 8 ms 14516 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 14428 KB Output is correct
2 Correct 7 ms 14420 KB Output is correct
3 Correct 7 ms 14336 KB Output is correct
4 Correct 7 ms 14432 KB Output is correct
5 Correct 7 ms 14420 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 14600 KB Output is correct
9 Correct 9 ms 14548 KB Output is correct
10 Correct 8 ms 14516 KB Output is correct
11 Correct 204 ms 33484 KB Output is correct
12 Correct 183 ms 34108 KB Output is correct
13 Correct 160 ms 33356 KB Output is correct
14 Correct 174 ms 33768 KB Output is correct
15 Correct 195 ms 34136 KB Output is correct
16 Correct 133 ms 32484 KB Output is correct
17 Correct 179 ms 33512 KB Output is correct
18 Correct 160 ms 43340 KB Output is correct
19 Correct 171 ms 34464 KB Output is correct
20 Correct 171 ms 34252 KB Output is correct