oj.uz

답안 #482527

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
482527 2021-10-25T11:09:43 Z jalsol Papričice (COCI20_papricice) C++17
110 / 110
 272 ms 33920 KB 
#ifdef LOCAL
#include "local.h"
#else
#include <bits/stdc++.h>
#define debug(...)
#define DB(...)
#endif

using namespace std;

using ll = long long;
using ld = long double;

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

#define For(i, l, r) for (int i = (l); i <= (r); ++i)
#define Ford(i, r, l) for (int i = (r); i >= (l); --i)
#define Rep(i, n) For (i, 0, (n) - 1)
#define Repd(i, n) Ford (i, (n) - 1, 0)
#define Fe(...) for (auto __VA_ARGS__)

template <class C> inline int isz(const C& c) { return static_cast<int>(c.size()); }
template <class T> inline bool chmin(T& a, const T& b) { return (a > b) ? a = b, true : false; }
template <class T> inline bool chmax(T& a, const T& b) { return (a < b) ? a = b, true : false; }

const bool __initialization = []() {
    cin.tie(nullptr)->sync_with_stdio(false);
#define TASK "empty"
    if (fopen(TASK".inp", "r")) {
        (void)(!freopen(TASK".inp", "r", stdin));
        (void)(!freopen(TASK".out", "w", stdout)); }
    cout << setprecision(12) << fixed;
    return true;
}();

constexpr ld eps = 1e-9;
constexpr int inf = 1e9;
constexpr ll linf = 1e18;

// =============================================================================

constexpr int maxn = 2e5 + 5;

int n;
vector<int> g[maxn];

int sz[maxn];

void DfsSize(int u, int p) {
    sz[u] = 1;

    Fe (v : g[u]) {
        if (v != p) {
            DfsSize(v, u);
            sz[u] += sz[v];
        }
    }
}

multiset<int> in, out;

vector<int> findClosest(const multiset<int>& st, int val) {
    vector<int> ret;
    auto it = st.upper_bound(val);

    if (it != st.end()) {
        ret.push_back(*it);
    }
    if (it != st.begin()) {
        ret.push_back(*(--it));
    }

    return ret;
}

int findDiff(int a, int b, int c) {
    array<int, 3> temp = { a, b, c };
    sort(all(temp));
    return temp[2] - temp[0];
}

int Dfs(int u, int p) {
    int ret = inf;
    vector<int> closest;

    {
        closest = findClosest(in, (n + sz[u]) / 2);
        Fe (vsz : closest) {
            chmin(ret, findDiff(sz[u], vsz - sz[u], n - vsz));
        }
    }
    {
        closest = findClosest(out, (n - sz[u]) / 2);
        Fe (vsz : closest) {
            chmin(ret, findDiff(sz[u], vsz, n - sz[u] - vsz));
        }
    }

    in.insert(sz[u]);
    Fe (v : g[u]) {
        if (v != p) {
            chmin(ret, Dfs(v, u));
        }
    }
    in.erase(in.find(sz[u]));
    out.insert(sz[u]);

    return ret;
}

signed main() {
    cin >> n;
    For (i, 1, n - 1) {
        int u, v; cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    DfsSize(1, -1);

    cout << Dfs(1, -1) << '\n';
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 2 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct

Subtask #2
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 2 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 4 ms 5068 KB Output is correct
7 Correct 5 ms 5068 KB Output is correct
8 Correct 6 ms 5068 KB Output is correct
9 Correct 3 ms 5068 KB Output is correct
10 Correct 3 ms 5068 KB Output is correct

Subtask #3
60.0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 2 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 4 ms 5068 KB Output is correct
7 Correct 5 ms 5068 KB Output is correct
8 Correct 6 ms 5068 KB Output is correct
9 Correct 3 ms 5068 KB Output is correct
10 Correct 3 ms 5068 KB Output is correct
11 Correct 242 ms 21552 KB Output is correct
12 Correct 250 ms 22904 KB Output is correct
13 Correct 207 ms 23544 KB Output is correct
14 Correct 218 ms 23252 KB Output is correct
15 Correct 272 ms 22868 KB Output is correct
16 Correct 174 ms 23688 KB Output is correct
17 Correct 240 ms 23032 KB Output is correct
18 Correct 232 ms 33920 KB Output is correct
19 Correct 227 ms 23284 KB Output is correct
20 Correct 264 ms 22920 KB Output is correct