Submission #544604

#	Time	Username	Problem	Language	Result	Execution time	Memory
544604		rainboy	Ball Machine (BOI13_ballmachine)	C11	100 / 100	119 ms	18388 KiB

ballmachine

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N	100000
#define N_	(1 << 17)	/* N_ = pow2(ceil(log2(N))) */

unsigned int X = 12345;

int rand_() {
	return (X *= 3) >> 1;
}

int min(int a, int b) { return a < b ? a : b; }

int *oj[N], oo[N];

void append(int i, int j) {
	int o = oo[i]++;

	if (o >= 2 && (o & o - 1) == 0)
		oj[i] = (int *) realloc(oj[i], o * 2 * sizeof *oj[i]);
	oj[i][o] = j;
}

int pp[N], qq[N], dd[N], sz[N], jj[N], dp[N], qu[N], cnt;

void dfs1(int i, int d) {
	int o, j_;

	qu[cnt++] = i;
	j_ = -1;
	dd[i] = d, sz[i] = 1, dp[i] = i;
	for (o = 0; o < oo[i]; o++) {
		int j = oj[i][o];

		dfs1(j, d + 1);
		if (j_ == -1 || sz[j_] < sz[j])
			j_ = j;
		sz[i] += sz[j];
		dp[i] = min(dp[i], dp[j]);
	}
	jj[i] = j_;
	if (j_ != -1)
		qq[j_] = -1;
}

int lca_(int i, int j) {
	int i_ = i, a;

	while (qq[i] != qq[j])
		if (dd[qq[i]] > dd[qq[j]])
			i = pp[qq[i]];
		else
			j = pp[qq[j]];
	a = dd[i] < dd[j] ? i : j;
	i = qq[i_];
	while (dd[i] > dd[a] + 1)
		i = qq[pp[i]];
	return dd[i] == dd[a] + 1 ? i : jj[a];
}

void sort(int *ii, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (dp[ii[j]] == dp[i_])
				j++;
			else if (dp[ii[j]] < dp[i_]) {
				tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
			}
		sort(ii, l, i);
		l = k;
	}
}

int hh[N];

void dfs2(int i) {
	int o;

	sort(oj[i], 0, oo[i]);
	for (o = 0; o < oo[i]; o++) {
		int j = oj[i][o];

		dfs2(j);
	}
	hh[qu[cnt] = i] = cnt, cnt++;
}

int st[N_ * 2], h_, n_; char lz[N_];

void put(int i) {
	st[i] = 0;
	if (i < n_)
		lz[i] = 1;
}

void pus(int i) {
	if (lz[i]) {
		put(i << 1), put(i << 1 | 1);
		lz[i] = 0;
	}
}

void pul(int i) {
	if (!lz[i])
		st[i] = st[i << 1] + st[i << 1 | 1];
}

void push(int i) {
	int h;

	for (h = h_; h > 0; h--)
		pus(i >> h);
}

void pull(int i) {
	while (i > 1)
		pul(i >>= 1);
}

void build(int n) {
	int i;

	h_ = 0;
	while (1 << h_ < n)
		h_++;
	n_ = 1 << h_;
	for (i = 0; i < n; i++)
		st[n_ + i] = 1;
	for (i = n_ - 1; i > 0; i--)
		pul(i);
}

int find(int k) {
	int i = 1;

	while (i < n_) {
		pus(i);
		i <<= 1;
		if (k > st[i])
			k -= st[i], i ^= 1;
	}
	return i - n_;
}

void update(int r) {
	int l = 0, l_ = l += n_, r_ = r += n_;

	push(l_), push(r_);
	for ( ; l <= r; l >>= 1, r >>= 1) {
		if ((l & 1) == 1)
			put(l++);
		if ((r & 1) == 0)
			put(r--);
	}
	pull(l_), pull(r_);
}

void upd(int i) {
	push(i += n_);
	st[i] = 1;
	pull(i);
}

int higher(int l) {
	int r = n_ - 1, l_ = l += n_, r_ = r += n_;

	push(l_), push(r_);
	for ( ; l <= r; l >>= 1, r >>= 1)
		if ((l & 1) == 1) {
			if (st[l] > 0) {
				while (l < n_) {
					pus(l);
					l = st[l << 1] > 0 ? l << 1 : l << 1 | 1;
				}
				return l - n_;
			}
			l++;
		}
	return -1;
}

int main() {
	int n, q, h, i, r;

	scanf("%d%d", &n, &q);
	r = -1;
	for (i = 0; i < n; i++)
		oj[i] = (int *) malloc(2 * sizeof *oj[i]);
	for (i = 0; i < n; i++) {
		scanf("%d", &pp[i]), pp[i]--;
		if (pp[i] == -1)
			r = i;
		else
			append(pp[i], i);
	}
	dfs1(r, 0);
	for (h = 0; h < cnt; h++) {
		i = qu[h];
		qq[i] = qq[i] ? qq[pp[i]] : i;
	}
	cnt = 0;
	dfs2(r);
	build(n);
	while (q--) {
		int t;

		scanf("%d", &t);
		if (t == 1) {
			int k;

			scanf("%d", &k);
			h = find(k);
			update(h);
			printf("%d\n", qu[h] + 1);
		} else {
			int p;

			scanf("%d", &i), i--;
			h = higher(hh[i]);
			p = h == -1 ? r : lca_(i, qu[h]);
			upd(hh[p]);
			printf("%d\n", dd[i] - dd[p]);
		}
	}
	return 0;
}

Compilation message (stderr)

ballmachine.c: In function 'append':
ballmachine.c:21:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   21 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
ballmachine.c: In function 'main':
ballmachine.c:193:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  193 |  scanf("%d%d", &n, &q);
      |  ^~~~~~~~~~~~~~~~~~~~~
ballmachine.c:198:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  198 |   scanf("%d", &pp[i]), pp[i]--;
      |   ^~~~~~~~~~~~~~~~~~~
ballmachine.c:215:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  215 |   scanf("%d", &t);
      |   ^~~~~~~~~~~~~~~
ballmachine.c:219:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  219 |    scanf("%d", &k);
      |    ^~~~~~~~~~~~~~~
ballmachine.c:226:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  226 |    scanf("%d", &i), i--;
      |    ^~~~~~~~~~~~~~~

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