Submission #441919

#	Time	Username	Problem	Language	Result	Execution time	Memory
441919		rainboy	Pyramid Base (IOI08_pyramid_base)	C11	75 / 100	5054 ms	38464 KiB

pyramid_base

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

#define N_	(1 << 20)	/* N_ = pow2(ceil(log2(M))) */
#define M	1000000
#define P	400000

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

int xmin[P], xmax[P], ymin[P], ymax[P], imin[P], imax[P], cc[P], m, n, p, a, b;

int iay[P * 2][3];

int compare_ymin(const void *a, const void *b) {
	int i = *(int *) a;
	int j = *(int *) b;

	return ymin[i] - ymin[j];
}

int compare_ymax(const void *a, const void *b) {
	int i = *(int *) a;
	int j = *(int *) b;

	return ymax[i] - ymax[j];
}

int st[N_ * 2], lz[N_ * 2];

void update(int l, int r, int x) {
	int l_ = l += N_, r_ = r += N_;

	if (l > r)
		return;
	for ( ; l <= r; l >>= 1, r >>= 1) {
		if ((l & 1) == 1)
			st[l] += x, lz[l] += x, l++;
		if ((r & 1) == 0)
			st[r] += x, lz[r] += x, r--;
	}
	while (l_ > 1)
		l_ >>= 1, st[l_] = min(st[l_ << 1 | 0], st[l_ << 1 | 1]) + lz[l_];
	while (r_ > 1)
		r_ >>= 1, st[r_] = min(st[r_ << 1 | 0], st[r_ << 1 | 1]) + lz[r_];
}

void merge() {
	int h, i, j;

	for (i = j = 0; (h = i + j) < p + p; ) {
		int *zz = iay[h];

		if (j == p)
			zz[1] = 1, zz[2] = ymin[zz[0] = imin[i++]] - a + 1;
		else if (i == p)
			zz[1] = 0, zz[2] = ymax[zz[0] = imax[j++]] + 1;
		else {
			int y1 = ymin[imin[i]] - a + 1, y0 = ymax[imax[j]] + 1;

			if (y1 < y0)
				zz[0] = imin[i++], zz[1] = 1, zz[2] = y1;
			else
				zz[0] = imax[j++], zz[1] = 0, zz[2] = y0;
		}
	}
}

int check() {
	int h, j, zero;

	memset(st, 0, N_ * 2 * sizeof *st), memset(lz, 0, N_ * 2 * sizeof *lz);
	update(m - a + 1, N_ - 1, b + 1);
	merge();
	zero = 0;
	for (h = 0; h < p * 2; h = j) {
		int y = iay[h][2];

		if (y + a - 1 >= n)	/* top boundary */
			break;
		if (!zero && y > 0) {
			zero = 1;
			if (st[1] <= b)
				return 1;
		}
		for (j = h; j < p * 2 && iay[j][2] == y; j++) {
			int i_ = iay[j][0];

			update(max(xmin[i_] - a + 1, 0), min(xmax[i_], m - a), iay[j][1] ? cc[i_] : -cc[i_]);
		}
		if (y < 0)	/* bottom boundary */
			continue;
		if (st[1] <= b)
			return 1;
	}
	return 0;
}

int main() {
	int i, lower, upper;

	scanf("%d%d%d%d", &m, &n, &b, &p);
	for (i = 0; i < p; i++) {
		int x1, y1, x2, y2, c;

		scanf("%d%d%d%d%d", &x1, &y1, &x2, &y2, &c), x1--, x2--, y1--, y2--;
		xmin[i] = x1, xmax[i] = x2, ymin[i] = y1, ymax[i] = y2, cc[i] = c;
		imin[i] = imax[i] = i;
	}
	qsort(imin, p, sizeof *imin, compare_ymin);
	qsort(imax, p, sizeof *imax, compare_ymax);
	if (check()) {
		lower = 1, upper = (m < n ? m : n) + 1;
		while (upper - lower > 1) {
			a = (lower + upper) / 2;
			if (check())
				lower = a;
			else
				upper = a;
		}
	} else
		lower = 0;
	printf("%d\n", lower);
	return 0;
}

Compilation message (stderr)

pyramid_base.c: In function 'main':
pyramid_base.c:104:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |  scanf("%d%d%d%d", &m, &n, &b, &p);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pyramid_base.c:108:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |   scanf("%d%d%d%d%d", &x1, &y1, &x2, &y2, &c), x1--, x2--, y1--, y2--;
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 0 / 5
• Subtask 7: 5 / 5
• Subtask 8: 7 / 7
• Subtask 9: 7 / 7
• Subtask 10: 7 / 7
• Subtask 11: 7 / 7
• Subtask 12: 7 / 7
• Subtask 13: 10 / 10
• Subtask 14: 0 / 10
• Subtask 15: 0 / 10