Submission #403909

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
403909	2021-05-13T14:58:05 Z	rainboy	Dancing Elephants (IOI11_elephants)	C	97 / 100	9000 ms	21172 KB

elephants

#include "elephants.h"
#include <string.h>

#define N	150000
#define LN	17	/* LN = floor(log2(N)) */
#define K	256
#define INF	0x3f3f3f3f

unsigned int X = 12345;

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

int xx[N * 2], ii[N], n, d;

int compare(int i, int j) { return xx[i] != xx[j] ? xx[i] - xx[j] : i - j; }

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) {
			int c = compare(ii[j], i_);

			if (c == 0)
				j++;
			else if (c < 0) {
				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 pp[N + 1][LN + 1], jump[N], ii_[K * 2], k, k1;

void build() {
	static int ii1[N];
	int n_, n1, k_, g, i, j, l;

	n_ = 0;
	for (i = 0; i < n; i++)
		if (xx[n + ii[i]] == -1)
			ii[n_++] = ii[i];
	k_ = 0;
	for (g = 0; g < k; g++)
		if (ii_[g] >= n)
			xx[ii_[g] - n] = xx[ii_[g]], xx[ii_[g]] = -1, ii_[k_++] = ii_[g] - n;
	i = 0, j = 0, n1 = 0;
	while (i < n_ || j < k_)
		ii1[n1++] = i < n_ && (j == k_ || compare(ii[i], ii_[j]) < 0) ? ii[i++] : ii_[j++];
	memcpy(ii, ii1, n * sizeof *ii1);
	for (i = 0, j = 0; i < n; i++) {
		while (j < n && xx[ii[j]] - xx[ii[i]] <= d)
			j++;
		pp[i][0] = j;
	}
	pp[n][0] = n;
	for (i = n; i >= 0; i--)
		for (l = 1, j = pp[i][0]; l <= LN; l++)
			j = pp[i][l] = pp[j][l - 1];
	k = 0;
}

void init(int n_, int d_, int *xx_) {
	int i;

	n = n_, d = d_;
	for (i = 0; i < n; i++)
		ii[i] = i;
	sort(ii, 0, n);
	memcpy(xx, xx_, n * sizeof *xx_), memset(xx + n, -1, n * sizeof *xx);
	build();
}

void bubble(int i) {
	int g, tmp;

	for (g = 0; g < k; g++)
		if (ii_[g] == i)
			break;
	while (g > 0 && compare(ii_[g], ii_[g - 1]) < 0)
		tmp = ii_[g], ii_[g] = ii_[g - 1], ii_[g - 1] = tmp, g--;
	while (g + 1 < k && compare(ii_[g], ii_[g + 1]) > 0)
		tmp = ii_[g], ii_[g] = ii_[g + 1], ii_[g + 1] = tmp, g++;
}

int solve() {
	int g, x, h, h_, l, ans;

	ans = 0;
	for (g = 0, x = -INF, h = 0; g < k; g++) {
		int i_ = ii_[g];

		if (h < n && (xx[ii[h]] < xx[i_] || xx[ii[h]] == xx[i_] && ii[h] < i_)) {
			for (l = LN; l >= 0; l--) {
				h_ = pp[h][l];
				if (h_ < n && (xx[ii[h_]] < xx[i_] || xx[ii[h_]] == xx[i_] && ii[h_] < i_))
					ans += 1 << l, h = h_;
			}
			ans++, x = xx[ii[h]], h = pp[h][0];
		}
		if (xx[i_] - x <= d)
			continue;
		if (i_ < n)
			h++;
		else
			ans++, x = xx[i_], h = jump[i_ - n];
	}
	if (h < n) {
		for (l = LN; l >= 0; l--)
			if (pp[h][l] < n)
				ans += 1 << l, h = pp[h][l];
		ans++;
	}
	return ans;
}

int update(int i, int y) {
	int lower, upper;

	if (k1 == K)
		build(), k1 = 0;
	k1++;
	if (xx[n + i] == -1) {
		ii_[k++] = i, bubble(i);
		ii_[k++] = n + i, xx[n + i] = y, bubble(n + i);
	} else
		xx[n + i] = y, bubble(n + i);
	lower = -1, upper = n;
	while (upper - lower > 1) {
		int h = (lower + upper) / 2;

		if (xx[ii[h]] - xx[n + i] <= d)
			lower = h;
		else
			upper = h;
	}
	jump[i] = upper;
	return solve();
}

Compilation message

elephants.c: In function 'solve':
elephants.c:101:59: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  101 |   if (h < n && (xx[ii[h]] < xx[i_] || xx[ii[h]] == xx[i_] && ii[h] < i_)) {
      |                                       ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
elephants.c:104:64: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  104 |     if (h_ < n && (xx[ii[h_]] < xx[i_] || xx[ii[h_]] == xx[i_] && ii[h_] < i_))
      |                                           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

Subtask #1

10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct

Subtask #2

16.0 / 16.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	344 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct

Subtask #3

24.0 / 24.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	344 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct
7	Correct	263 ms	2076 KB	Output is correct
8	Correct	307 ms	2488 KB	Output is correct
9	Correct	1096 ms	5608 KB	Output is correct
10	Correct	645 ms	5580 KB	Output is correct
11	Correct	616 ms	5612 KB	Output is correct
12	Correct	2438 ms	5612 KB	Output is correct
13	Correct	575 ms	5608 KB	Output is correct

Subtask #4

47.0 / 47.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	344 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct
7	Correct	263 ms	2076 KB	Output is correct
8	Correct	307 ms	2488 KB	Output is correct
9	Correct	1096 ms	5608 KB	Output is correct
10	Correct	645 ms	5580 KB	Output is correct
11	Correct	616 ms	5612 KB	Output is correct
12	Correct	2438 ms	5612 KB	Output is correct
13	Correct	575 ms	5608 KB	Output is correct
14	Correct	936 ms	2784 KB	Output is correct
15	Correct	497 ms	3332 KB	Output is correct
16	Correct	3321 ms	5848 KB	Output is correct
17	Correct	3961 ms	7744 KB	Output is correct
18	Correct	4022 ms	7716 KB	Output is correct
19	Correct	1308 ms	7756 KB	Output is correct
20	Correct	4119 ms	7688 KB	Output is correct
21	Correct	4248 ms	7720 KB	Output is correct
22	Correct	1062 ms	7736 KB	Output is correct

Subtask #5

0 / 3.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	332 KB	Output is correct
2	Correct	1 ms	332 KB	Output is correct
3	Correct	1 ms	332 KB	Output is correct
4	Correct	1 ms	332 KB	Output is correct
5	Correct	1 ms	344 KB	Output is correct
6	Correct	1 ms	332 KB	Output is correct
7	Correct	263 ms	2076 KB	Output is correct
8	Correct	307 ms	2488 KB	Output is correct
9	Correct	1096 ms	5608 KB	Output is correct
10	Correct	645 ms	5580 KB	Output is correct
11	Correct	616 ms	5612 KB	Output is correct
12	Correct	2438 ms	5612 KB	Output is correct
13	Correct	575 ms	5608 KB	Output is correct
14	Correct	936 ms	2784 KB	Output is correct
15	Correct	497 ms	3332 KB	Output is correct
16	Correct	3321 ms	5848 KB	Output is correct
17	Correct	3961 ms	7744 KB	Output is correct
18	Correct	4022 ms	7716 KB	Output is correct
19	Correct	1308 ms	7756 KB	Output is correct
20	Correct	4119 ms	7688 KB	Output is correct
21	Correct	4248 ms	7720 KB	Output is correct
22	Correct	1062 ms	7736 KB	Output is correct
23	Correct	8433 ms	16152 KB	Output is correct
24	Execution timed out	9009 ms	21172 KB	Time limit exceeded
25	Halted	0 ms	0 KB	-