Submission #993391

#	Time	Username	Problem	Language	Result	Execution time	Memory
993391		vyshniak_n	Tax Evasion (LMIO19_mokesciai)	C++17	100 / 100	280 ms	139284 KiB

mokesciai

//#pragma optimize("Ofast")
//#pragma optimize("unroll-loops")
//#pragma traget("avx,avx2")

#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <cstdint>
#include <cstring>
#include <string>
#include <cstdlib>
#include <vector>
#include <bitset>
#include <map>
#include <queue>
#include <ctime>
#include <stack>
#include <set>
#include <list>
#include <random>
#include <deque>
#include <functional>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <complex>
#include <numeric>
#include <cassert>
#include <array>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <thread>

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define el '\n'
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define point pair <ll, ll>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

using namespace std;

#include <random>
mt19937 rnd(time(0));

const ll INF = 1e18 + 10;
const ll inf = 1e9 + 10;
const ll maxn = 2e5 + 10;
const ll mod = 1e9 + 7;
const ll K = 7e6 + 100;
const ll LOG = 20;

vector <ll> gr[maxn];
ll up[maxn][LOG], deep[maxn];
void dfs(ll v, ll pr) {
    up[v][0] = pr;
    for (ll i = 1; i < LOG; i++)
        up[v][i] = up[ up[v][i - 1] ][i - 1];

    for (ll to : gr[v]) {
        if (to == pr)
            continue;

        deep[to] = deep[v] + 1;
        dfs(to, v);
    }
}

ll cnt[maxn], id[maxn], ans = inf;
multiset <ll> leaf[maxn];
void calc(ll v, ll pr) {
    id[v] = v;
    for (ll to : gr[v]) {
        if (to == pr)
            continue;

        calc(to, v);
        if (leaf[id[v]].size() < leaf[id[to]].size())
            id[v] = id[to];
    }

    leaf[id[v]].insert(deep[v]);
    for (ll to : gr[v]) {
        if (to == pr || id[v] == id[to])
            continue;
        for (auto it : leaf[id[to]])
            leaf[id[v]].insert(it);
    }

    while (cnt[v]) {
        cnt[v]--;

        auto it = leaf[id[v]].end();
        it--;

        ans = min(ans, *it);
        leaf[id[v]].erase(it);
    }
}

void solve() {
    ll n, m;
    cin >> n >> m;

    for (ll i = 2; i <= n; i++) {
        ll p;
        cin >> p;

        gr[i].pb(p);
        gr[p].pb(i);
    }

    bool ok = 0;

    dfs(1, 1);
    for (ll i = 1; i <= m; i++) {
        ll v, rem;
        cin >> v;

        rem = v;

        if (v == 1)
            ok = 1;

        for (ll j = LOG - 1; j >= 0; j--)
            if (deep[rem] < deep[up[v][j]] * 2)
                v = up[v][j];

        cnt[v]++;
    }

    if (ok)
        return void(cout << 1 << el);

    calc(1, 1);
    cout << ans + 1 << el;
    return;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int tests = 1;
    //cin >> tests;

    while (tests--) 
        solve();
    return 0;
}
/*
*/

• Subtask 1: 10 / 10
• Subtask 2: 22 / 22
• Subtask 3: 39 / 39
• Subtask 4: 29 / 29