Submission #1125838

#	Time	Username	Problem	Language	Result	Execution time	Memory
1125838		underwaterkillerwhale	Papričice (COCI20_papricice)	C++20	110 / 110	116 ms	32940 KiB

papricice

//#include"holiday.h"
#include <bits/stdc++.h>
#define ll long long
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define REB(i,m,n) for(int i=(m); i>=(n); i--)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MP make_pair
#define fs first
#define se second
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define pb push_back
#define SZ(v) (ll)v.size()
#define ALL(v) v.begin(),v.end()

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now ().time_since_epoch().count());
ll Rand (ll l, ll r) { return uniform_int_distribution<ll> (l, r) (rd); }

const int N = 2e5 + 7;
const int Mod = 1e9 + 7;///lon
const int INF = 1e9 + 7;
const ll BASE = 137;
const int szBL = 450;

int n, m;
vector<int> ke[N];
int szC[N];
set<int> S[N];
int res = INF;

int Find (int sz1, int rem, set<int> &cur) {
    int res = INF;
    auto it = cur.lower_bound(rem / 2);
    if (it != cur.end()) {
        int sz2 = *it, sz3 = rem - sz2;
//        cout << sz1 <<" "<<sz2 <<" "<<sz3 <<"\n";
        res = min(res, max({sz1, sz2, sz3}) - min({sz1, sz2, sz3}));
    }
    if (it != cur.begin()) {
        int sz2 = *prev(it), sz3 = rem - sz2;
        res = min(res, max({sz1, sz2, sz3}) - min({sz1, sz2, sz3}));
    }
    return res;
}

void dfs (int u, int p) {
    szC[u] = 1;
    iter (&v, ke[u]) {
        if (v != p) {
            dfs(v, u);
            szC[u] += szC[v];
            if (SZ(S[u]) < SZ(S[v]))
                swap(S[u], S[v]);
            iter (&id, S[v]) {
                res = min(res, Find(id, n - id, S[u]));
            }
            iter (&id, S[v]) {
                S[u].insert(id);
            }
            set<int> ().swap(S[v]);
        }
    }
    S[u].insert(szC[u]);
    if (p != 0) {
        res = min(res, Find(n - szC[u], szC[u], S[u]));
    }
}

void solution () {
    cin >> n;
    rep (i, 1, n - 1) {
        int u, v;
        cin >> u >> v;
        ke[u].pb(v);
        ke[v].pb(u);
    }
    dfs (1, 0);
    cout << res <<"\n";
}

#define file(name) freopen(name".inp","r",stdin); \
freopen(name".out","w",stdout);
int main () {
//    file("c");
    ios_base :: sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int num_Test = 1;
//    cin >> num_Test;
    while (num_Test--)
        solution();
}
/*
no bug challenge +33
rep (i, 0, n) {
    rep (j, 0, i) {
        if (j == 0 || j == i) {
            C[j][i] = 1;
            continue;
        }
        C[j][i] = (C[j][i - 1] + C[j - 1][i - 1]) % Mod;
    }
}
*/

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