Submission #1108346

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108346		Kirill22	Ball Machine (BOI13_ballmachine)	C++17	100 / 100	337 ms	28848 KiB

ballmachine

#include "bits/stdc++.h"

using namespace std;

const int N = (int) 1e5 + 22;
vector<int> g[N];
int n, q, dp[N], rt, uk = 0, ord[N], up[N][20];

void dfs(int v) {
    dp[v] = v;
    for (int j = 1; j < 20; j++) {
        if (up[v][j - 1] == -1) {
            up[v][j] = -1;
            continue;
        }
        up[v][j] = up[up[v][j - 1]][j - 1];
    }
    for (auto u : g[v]) {
        up[u][0] = v;
        dfs(u);
        dp[v] = min(dp[v], dp[u]);
    }
    std::sort(g[v].begin(), g[v].end(), [&] (int x, int y) { return dp[x] < dp[y]; });
}

void dfs2(int v) {
    for (auto u : g[v]) {
        dfs2(u);
    }
    ord[v] = uk++;
}

void solve() {
    cin >> n >> q;
    for (int i = 0; i < n; i++) {
        int p;
        cin >> p;
        p--;
        if (p == -1) {
            rt = i;
        } else {
            g[p].push_back(i);
        }
    }
    up[rt][0] = -1;
    dfs(rt);
    dfs2(rt);
    set<pair<int, int>> life;
    for (int i = 0; i < n; i++) {
        life.insert({ord[i], i});
    }
    while (q--) {
        int t, x;
        cin >> t >> x;
        if (t == 1) {
            int ans = 0;
            while (x--) {
                int v = life.begin()->second;
                ans = v;
                life.erase(life.begin());
            }
            cout << ans + 1 << '\n';
        } else {
            x--;
            int v = x, dist = 0;
            for (int j = 19; j >= 0; j--) {
                int u = up[v][j];
                if (u == -1) {
                    continue;
                }
                if (life.find({ord[u], u}) == life.end()) {
                    dist += (1 << j);
                    v = u;
                }
            }
            life.insert({ord[v], v});
            cout << dist << '\n';
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
//    cin >> t;
    while (t--) {
        solve();
    }
}

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