Submission #482519

#	Time	Username	Problem	Language	Result	Execution time	Memory
482519		jalsol	Papričice (COCI20_papricice)	C++17	50 / 110	1067 ms	17800 KiB

papricice

#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;

struct Edge {
    int u, v;
    int other(int x) const { return u ^ v ^ x; }
};

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

int sz[maxn];
int color[maxn];
int par[maxn];

void Dfs(int u, int c) {
    sz[u] = 1;

    Fe (id : g[u]) {
        if (color[id]) continue;

        color[id] = c;
        int v = e[id].other(u);

        par[v] = u;
        Dfs(v, c);
        sz[u] += sz[v];
    }
}

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

    int ans = n;

    For (i, 1, n - 1) {
        auto [u, v] = e[i];
        memset(color + 1, 0, 4 * (n - 1));
        color[i] = -1;

        par[u] = -1;
        Dfs(u, 1);

        par[v] = -1;
        Dfs(v, 2);

        int subu = sz[u];
        int subv = sz[v];

        For (j, 1, n - 1) {
            if (i == j) continue;

            auto [pu, pv] = e[j];
            if (pv == par[pu]) swap(pu, pv);
            array<int, 3> comp;

            if (color[j] == 1) {
                comp = { subv, sz[pv], subu - sz[pv] };
            }
            else {
                comp = { subu, sz[pv], subv - sz[pv] };
            }

            sort(all(comp));

            int diff = comp[2] - comp[0];
            chmin(ans, diff);
        }
    }

    cout << ans << '\n';
}

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 0 / 60