Submission #924278

#	Time	Username	Problem	Language	Result	Execution time	Memory
924278		rainboy	장애물 경기 (KOI16_dd)	C11	100 / 100	92 ms	9920 KiB

dd

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

#define N	100001
#define N_	(1 << 18)	/* N_ = pow2(ceil(log2(N * 2))) */

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

unsigned int X = 12345;

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

int xx[N], yy[N * 2], yy_[N * 2], hh[N * 2];
int *ww;

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 (ww[ii[j]] == ww[i_])
				j++;
			else if (ww[ii[j]] < ww[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 st[N_ * 2], n_;

int min_(int i, int j) { return j == -1 || i != -1 && xx[i] < xx[j] ? i : j; }

void update(int l, int r, int x) {
	for (l += n_, r += n_; l <= r; l >>= 1, r >>= 1) {
		if ((l & 1) == 1)
			st[l] = min_(st[l], x), l++;
		if ((r & 1) == 0)
			st[r] = min_(st[r], x), r--;
	}
}

int query(int i) {
	int x = -1;

	for (i += n_; i > 0; i >>= 1)
		x = min_(x, st[i]);
	return x;
}

int main() {
	static int ii[N * 2], jj[N * 2], dp[N * 2];
	static char used[N * 2], used_[N * 2];
	int n, m, x, y, y_, h, i, i0, i1, j, j0, j1, k;

	scanf("%d%d%d", &n, &y_, &x), n++;
	xx[0] = 0, yy[0 << 1 | 0] = y_, yy[0 << 1 | 1] = y_;
	for (i = 1; i < n; i++)
		scanf("%d%d%d", &xx[i], &yy[i << 1 | 0], &yy[i << 1 | 1]);
	for (i = 0; i < n * 2; i++)
		ii[i] = i;
	ww = yy, sort(ii, 0, n * 2);
	m = 0;
	for (i = 0; i < n * 2; i = j) {
		j = i, y = yy[ii[i]];
		while (j < n * 2 && yy[ii[j]] == y)
			hh[ii[j++]] = m;
		yy_[m++] = y;
	}
	n_ = 1;
	while (n_ < n * 2)
		n_ <<= 1;
	memset(st, -1, n_ * 2 * sizeof *st);
	for (i = 0; i < n; i++)
		ii[i] = i;
	ww = xx, sort(ii, 0, n);
	for (h = n - 1; h >= 0; h--) {
		i = ii[h], i0 = i << 1 | 0, i1 = i << 1 | 1;
		j = jj[i0] = query(hh[i0]);
		if (j == -1)
			dp[i0] = 0;
		else {
			j0 = j << 1 | 0, j1 = j << 1 | 1;
			dp[i0] = min(dp[j0] + yy[i0] - yy[j0], dp[j1] + yy[j1] - yy[i0]);
		}
		j = jj[i1] = query(hh[i1]);
		if (j == -1)
			dp[i1] = 0;
		else {
			j0 = j << 1 | 0, j1 = j << 1 | 1;
			dp[i1] = min(dp[j0] + yy[i1] - yy[j0], dp[j1] + yy[j1] - yy[i1]);
		}
		update(hh[i0] + 1, hh[i1] - 1, i);
	}
	printf("%d\n", x + dp[0]);
	used[0 << 1 | 0] = used[0 << 1 | 1] = 1;
	for (h = 0; h < n; h++) {
		i = ii[h], i0 = i << 1 | 0, i1 = i << 1 | 1;
		i = ii[h];
		if (used[i0]) {
			j = jj[i0];
			if (j == -1)
				used_[hh[i0]] = 1;
			else {
				j0 = j << 1 | 0, j1 = j << 1 | 1;
				if (dp[i0] == dp[j0] + yy[i0] - yy[j0])
					used[j0] = 1;
				if (dp[i0] == dp[j1] + yy[j1] - yy[i0])
					used[j1] = 1;
			}
		}
		if (used[i1]) {
			j = jj[i1];
			if (j == -1)
				used_[hh[i1]] = 1;
			else {
				j0 = j << 1 | 0, j1 = j << 1 | 1;
				if (dp[i1] == dp[j0] + yy[i1] - yy[j0])
					used[j0] = 1;
				if (dp[i1] == dp[j1] + yy[j1] - yy[i1])
					used[j1] = 1;
			}
		}
	}
	k = 0;
	for (h = 0; h < m; h++)
		if (used_[h])
			k++;
	printf("%d", k);
	for (h = 0; h < m; h++)
		if (used_[h])
			printf(" %d", yy_[h]);
	printf("\n");
	return 0;
}

Compilation message (stderr)

dd.c: In function 'min_':
dd.c:39:52: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   39 | int min_(int i, int j) { return j == -1 || i != -1 && xx[i] < xx[j] ? i : j; }
      |                                            ~~~~~~~~^~~~~~~~~~~~~~~~
dd.c: In function 'main':
dd.c:63:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |  scanf("%d%d%d", &n, &y_, &x), n++;
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
dd.c:66:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |   scanf("%d%d%d", &xx[i], &yy[i << 1 | 0], &yy[i << 1 | 1]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 22 / 22
• Subtask 3: 29 / 29
• Subtask 4: 36 / 36