Submission #704743

#	Time	Username	Problem	Language	Result	Execution time	Memory
704743		rainboy	영역 (JOI16_ho_t4)	C11	100 / 100	107 ms	28280 KiB

2016_ho_t4

#include <stdio.h>

#define N	100000
#define N_	((N + 1) * 8)

unsigned int X = 12345;

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

long long cross(int x1, int y1, int x2, int y2) {
	return (long long) x1 * y2 - (long long) x2 * y1;
}

long long dot(int x1, int y1, int x2, int y2) {
	return (long long) x1 * x2 + (long long) y1 * y2;
}

long long xxp[N + 1], xxq[N + 1], yy[N + 1], xxp_[N_], xxq_[N_], yy_[N_], d_; int vv[N_], x_, y_;

long long *xxp1, *xxq1, *yy1;

int compare(int i, int j) {
	if (yy1[i] != yy1[j])
		return yy1[i] < yy1[j] ? -1 : 1;
	if (xxq1[i] != xxq1[j])
		return xxq1[i] < xxq1[j] ? -1 : 1;
	return xxp1[i] == xxp1[j] ? 0 : (xxp1[i] < xxp1[j] ? -1 : 1);
}

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 main() {
	static char cc[N + 1];
	static int ii[N + 1], ii_[N_];
	int n, n_, k, h, h_, i, j, x, y, v;
	long long d, ans;

	scanf("%d%d%s", &n, &k, cc);
	x_ = 0, y_ = 0;
	for (i = 0; i < n; i++)
		if (cc[i] == 'E')
			x_++;
		else if (cc[i] == 'W')
			x_--;
		else if (cc[i] == 'N')
			y_++;
		else
			y_--;
	if (x_ == 0 && y_ == 0)
		x_ = 1, y_ = 0, k = 1;
	d_ = dot(x_, y_, x_, y_);
	x = 0, y = 0;
	for (i = 0; i < n; i++) {
		if (cc[i] == 'E')
			x++;
		else if (cc[i] == 'W')
			x--;
		else if (cc[i] == 'N')
			y++;
		else
			y--;
		d = dot(x, y, x_, y_);
		xxq[i + 1] = d % d_;
		if (xxq[i + 1] < 0)
			xxq[i + 1] += d_;
		xxp[i + 1] = (d - xxq[i + 1]) / d_;
		yy[i + 1] = cross(x, y, x_, y_);
	}
	for (i = 0; i <= n; i++)
		ii[i] = i;
	xxp1 = xxp, xxq1 = xxq, yy1 = yy, sort(ii, 0, n + 1);
	n_ = 0;
	for (i = 0; i <= n; i = j) {
		long long xq = xxq[ii[i]], y = yy[ii[i]];

		j = i + 1;
		while (j <= n && xxq[ii[j]] == xq && yy[ii[j]] == y)
			j++;
		for (h = i; h < j; h = h_) {
			long long xp1, xq1, y1, xp2, xq2, y2;

			h_ = h + 1;
			while (h_ < j && xxp[ii[h_]] - xxp[ii[h_ - 1]] <= k)
				h_++;
			xp1 = xxp[ii[h]], xq1 = xq, y1 = y;
			xp2 = xxp[ii[h_ - 1]] + k, xq2 = xq, y2 = y;
			xxp_[n_] = xp1, xxq_[n_] = xq1, yy_[n_] = y1, vv[n_] = 1, n_++;
			xxp_[n_] = xp2, xxq_[n_] = xq2, yy_[n_] = y2, vv[n_] = -1, n_++;
			xq1 += y_;
			if (xq1 < 0)
				xp1--, xq1 += d_;
			if (xq1 >= d_)
				xp1++, xq1 -= d_;
			y1 -= x_;
			xq2 += y_;
			if (xq2 < 0)
				xp2--, xq2 += d_;
			if (xq2 >= d_)
				xp2++, xq2 -= d_;
			y2 -= x_;
			xxp_[n_] = xp1, xxq_[n_] = xq1, yy_[n_] = y1, vv[n_] = 1, n_++;
			xxp_[n_] = xp2, xxq_[n_] = xq2, yy_[n_] = y2, vv[n_] = -1, n_++;
			xq1 += x_;
			if (xq1 < 0)
				xp1--, xq1 += d_;
			if (xq1 >= d_)
				xp1++, xq1 -= d_;
			y1 += y_;
			xq2 += x_;
			if (xq2 < 0)
				xp2--, xq2 += d_;
			if (xq2 >= d_)
				xp2++, xq2 -= d_;
			y2 += y_;
			xxp_[n_] = xp1, xxq_[n_] = xq1, yy_[n_] = y1, vv[n_] = 1, n_++;
			xxp_[n_] = xp2, xxq_[n_] = xq2, yy_[n_] = y2, vv[n_] = -1, n_++;
			xq1 -= y_;
			if (xq1 < 0)
				xp1--, xq1 += d_;
			if (xq1 >= d_)
				xp1++, xq1 -= d_;
			y1 += x_;
			xq2 -= y_;
			if (xq2 < 0)
				xp2--, xq2 += d_;
			if (xq2 >= d_)
				xp2++, xq2 -= d_;
			y2 += x_;
			xxp_[n_] = xp1, xxq_[n_] = xq1, yy_[n_] = y1, vv[n_] = 1, n_++;
			xxp_[n_] = xp2, xxq_[n_] = xq2, yy_[n_] = y2, vv[n_] = -1, n_++;
		}
	}
	for (i = 0; i < n_; i++)
		ii_[i] = i;
	xxp1 = xxp_, xxq1 = xxq_, yy1 = yy_, sort(ii_, 0, n_);
	ans = 0;
	for (i = 0; i < n_; i = j) {
		long long xq = xxq_[ii_[i]], y = yy_[ii_[i]];

		j = i + 1;
		while (j < n_ && xxq_[ii_[j]] == xq && yy_[ii_[j]] == y)
			j++;
		v = 0;
		for (h = i; h + 1 < j; h++)
			if ((v += vv[ii_[h]]) == 4)
				ans += xxp_[ii_[h + 1]] - xxp_[ii_[h]];
	}
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

2016_ho_t4.c: In function 'main':
2016_ho_t4.c:60:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |  scanf("%d%d%s", &n, &k, cc);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 62 / 62