Submission #1064334

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064334		earlyamazon	Ball Machine (BOI13_ballmachine)	C++14	100 / 100	226 ms	28448 KiB

ballmachine

/**
 * @file msz2.cpp
 * @author random(usrnm: Pekiban) z oj.uz
 * @brief Wzo - O(n * logn)
 */

#include <bits/stdc++.h>

using namespace std;
#define pb push_back
#define lwb lower_bound

const int N = 1e5 + 5, LOG = 17;
vector<int> g[N];
int up[LOG][N], D[N], mn[N], ps[N];
vector<int> a = {-1};
void dfs1(int s, int e = -1)
{
    mn[s] = s;
    for (auto u : g[s])
    {
        if (u == e)
            continue;
        D[u] = D[s] + 1;
        up[0][u] = s;
        dfs1(u, s);
        mn[s] = min(mn[s], mn[u]);
    }
}
bool cmp(int x, int y)
{
    return mn[x] < mn[y];
}
void dfs2(int s, int e = -1)
{
    sort(g[s].begin(), g[s].end(), cmp);
    for (auto u : g[s])
    {
        if (u == e)
            continue;
        dfs2(u, s);
    }
    a.pb(s);
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n, q, R;
    cin >> n >> q;
    for (int i = 1; i <= n; ++i)
    {
        int p;
        cin >> p;
        if (i == 0)
        {
            R = i;
            continue;
        }
        g[p].pb(i);
        g[i].pb(p);
    }
    dfs1(R);
    dfs2(R);
    for (int i = 1; i < LOG; ++i)
    {
        for (int j = 1; j <= n; ++j)
        {
            up[i][j] = up[i - 1][up[i - 1][j]];
        }
    }
    for (int i = 1; i <= n; ++i)
        ps[a[i]] = i;
    ps[0] = 1e9;
    set<int> r, av;
    for (int i = 1; i <= n; ++i)
        av.insert(i);
    map<int, int> L;
    L[0] = 1;
    while (q--)
    {
        int t;
        cin >> t;
        if (t == 1)
        {
            int k, ans=0;
            cin >> k;
            while (k--)
            {
                int x = *av.begin();
                av.erase(x);
                if (r.lwb(x) == r.end() || x + 1 < L[*r.lwb(x)])
                {
                    L[x] = L[x - 1];
                    if (x > 1)
                        L.erase(x - 1);
                    if (x > 1)
                        r.erase(x - 1);
                    r.insert(x);
                }
                else
                {
                    L[*r.lwb(x)] = L[x - 1];
                    if (x > 1)
                        L.erase(x - 1);
                    if (x > 1)
                        r.erase(x - 1);
                }
                ans = x;
            }
            cout << a[ans] << '\n';
        }
        else
        {
            int x;
            cin >> x;
            int X = x, ri = *r.lwb(ps[x]);
            for (int i = LOG - 1; i >= 0; --i)
            {
                if (ps[up[i][x]] <= ri)
                    x = up[i][x];
            }
            L[ps[x] - 1] = L[ri];
            r.insert(ps[x] - 1);
            if (ps[x] - 1 < L[ps[x] - 1])
            {
                L.erase(ps[x] - 1);
                r.erase(ps[x] - 1);
            }
            L[ri] = ps[x] + 1;
            if (L[ri] > ri)
            {
                L.erase(ri);
                r.erase(ri);
            }
            av.insert(ps[x]);
            cout << D[X] - D[x] << '\n';
        }
    }
}

• Subtask 1: 25 / 25
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40
• Subtask 4: 5 / 5