Submission #536319

#	Time	Username	Problem	Language	Result	Execution time	Memory
536319		rainboy	물병 (JOI14_bottle)	C11	100 / 100	749 ms	105292 KiB

bottle

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

#define N	2000
#define M	2000
#define N_	200000
#define M_	(N * M * 4)
#define INF	0x3f3f3f3f

int di[] = { -1, 1, 0, 0 };
int dj[] = { 0, 0, -1, 1 };

unsigned int X = 12345;

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

int uu[M_], vv[M_], ww[M_], m_;

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

		while (j < k)
			if (ww[hh[j]] == ww[h])
				j++;
			else if (ww[hh[j]] < ww[h]) {
				tmp = hh[i], hh[i] = hh[j], hh[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = hh[j], hh[j] = hh[k], hh[k] = tmp;
			}
		sort(hh, l, i);
		l = k;
	}
}

int ds[N_], ww_[N_];

int find(int i) {
	return ds[i] < 0 ? i : find(ds[i]);
}

void join(int i, int j, int w) {
	i = find(i);
	j = find(j);
	if (i == j)
		return;
	if (ds[i] > ds[j])
		ds[i] = j, ww_[i] = w;
	else {
		if (ds[i] == ds[j])
			ds[i]--;
		ds[j] = i, ww_[j] = w;
	}
}

int query(int i, int j) {
	int w = 0;

	while (i != j && (ww_[i] != INF || ww_[j] != INF))
		if (ww_[i] < ww_[j])
			w = ww_[i], i = ds[i];
		else
			w = ww_[j], j = ds[j];
	return i != j ? -1 : w;
}

int main() {
	static char cc[N][M + 1];
	static int dd[N][M], uu_[N][M], qu[N * M], hh[M_];
	int n, n_, m, q, h, i, j, u, v, head, cnt;

	scanf("%d%d%d%d", &n, &m, &n_, &q);
	for (i = 0; i < n; i++)
		scanf("%s", cc[i]);
	for (i = 0; i < n; i++)
		for (j = 0; j < m; j++)
			dd[i][j] = n * m, uu_[i][j] = -1;
	head = cnt = 0;
	for (u = 0; u < n_; u++) {
		scanf("%d%d", &i, &j), i--, j--;
		dd[i][j] = 0, uu_[i][j] = u, qu[head + cnt++] = i * m + j;
	}
	while (cnt) {
		int ij, d;

		ij = qu[cnt--, head++], i = ij / m, j = ij % m, d = dd[i][j] + 1, u = uu_[i][j];
		for (h = 0; h < 4; h++) {
			int i_ = i + di[h], j_ = j + dj[h];

			if (i_ >= 0 && i_ < n && j_ >= 0 && j_ < m && cc[i_][j_] == '.') {
				if (dd[i_][j_] > d)
					dd[i_][j_] = d, uu_[i_][j_] = u, qu[head + cnt++] = i_ * m + j_;
				else if ((v = uu_[i_][j_]) != u)
					uu[m_] = u, vv[m_] = v, ww[m_] = d + dd[i_][j_] - 1, m_++;
			}
		}
	}
	for (h = 0; h < m_; h++)
		hh[h] = h;
	sort(hh, 0, m_);
	memset(ds, -1, n_ * sizeof *ds);
	memset(ww_, 0x3f, n_ * sizeof *ww_);
	for (h = 0; h < m_; h++)
		join(uu[hh[h]], vv[hh[h]], ww[hh[h]]);
	while (q--) {
		scanf("%d%d", &i, &j), i--, j--;
		printf("%d\n", query(i, j));
	}
	return 0;
}

Compilation message (stderr)

bottle.c: In function 'main':
bottle.c:76:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |  scanf("%d%d%d%d", &n, &m, &n_, &q);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bottle.c:78:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |   scanf("%s", cc[i]);
      |   ^~~~~~~~~~~~~~~~~~
bottle.c:84:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~
bottle.c:110:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30