Submission #872737

#	Time	Username	Problem	Language	Result	Execution time	Memory
872737		vjudge1	Ball Machine (BOI13_ballmachine)	C++17	83.68 / 100	1065 ms	40588 KiB

ballmachine

#include<bits/stdc++.h>
using namespace std;
 
#define int long long
#define F first
#define S second
#define pii pair<int, int>
#define pb push_back
#define pp pop_back
#define all(x) x.begin(), x.end()
 
const int N = 1e5 + 12, M = 20, SQ = 400;
vector<int> g[N];
int n, q, t, f[N], p[N], par[M][N], root, d[N], h[N], sum[SQ];
bool dp[SQ], a[SQ * SQ + 12];

void ip() {
	cin >> n >> q;
	for (int i = 0; i < n; i++) {
		int u;
		cin >> u;
		u--;
		par[0][i] = u;
		if (u == -1)
			root = i;
		else {
			g[u].pb(i);
			g[i].pb(u);
		}
	}
	par[0][root] = root;
}
 
void dfs1(int u) {
	d[u] = u;
	for (auto i: g[u])
		if (i != par[0][u]) {
			h[i] = h[u] + 1;
			dfs1(i);
			d[u] = min(d[u], d[i]);
		}
}
 
void dfs2(int u) {
	vector<pii> tmp;
	for (auto i: g[u])
		if (i != par[0][u])
			tmp.pb({d[i], i});
	sort(all(tmp));
	for (auto i: tmp)
		dfs2(i.S);
	f[t] = u;
	p[u] = t;
	t++;
}
 
void pre() {
	dfs1(root);
	dfs2(root);
	for (int i = 1; i < M; i++)
		for (int j = 0; j < n; j++)
			par[i][j] = par[i - 1][par[i - 1][j]];
}

void add(int x) {
	for (int i = 0; (i + 1) * SQ - 1 < x; i++) {
		sum[i] = SQ;
		dp[i] = true;
	}
	if (!dp[x / SQ]) 
		for (int i = (x / SQ) * SQ; i <= x; i++)
			if (!a[i]) {
				a[i] = true;
				sum[x / SQ]++;
			}
}

void rem(int x) {
	if (dp[x / SQ]) {
		fill(a + x - x % SQ, a + x - x % SQ + SQ, 1);
		sum[x / SQ] = SQ - 1;
		dp[x / SQ] = false;
		a[x] = false;
	}
	else if (a[x]) {
		a[x] = false;
		sum[x / SQ]--;
	}
}

int ask(int x) {
	int res = 0;
	for (int i = 0; (i + 1) * SQ - 1 < x; i++)
		res += sum[i];
	if (dp[x / SQ]) 
		res += (x % SQ) + 1;
	else 
		for (int i = x - x % SQ; i <= x; i++)
			res += a[i];
	return res;
}
 
void query() {
	while (q--) {
		int u, v;
		cin >> u >> v;
		if (u == 1) {
			int l = -1, r = n;
			while (r - l > 1) {
				int mid = (l + r) / 2;
				if (mid + 1 - ask(mid + 1) <= v)
					l = mid;
				else
					r = mid;
			}
			cout << f[l] + 1 << '\n';
			add(l);
		}
		else {
			v--;
			int z = v;
			for (int i = M - 1; ~i; i--)
				if ((ask(p[par[i][v]]) - ask(p[par[i][v]] - 1)) > 0)
					v = par[i][v];
			cout << h[z] - h[v] << '\n';
			rem(p[v]);
		}
	}
}
 
int32_t main() {
	ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	ip(), pre(), query();
	return 0;
}

• Subtask 1: 19.23076923076923 / 25
• Subtask 2: 25.714285714285715 / 30
• Subtask 3: 34.285714285714285 / 40
• Subtask 4: 4.444444444444445 / 5