Submission #946391

#	Time	Username	Problem	Language	Result	Execution time	Memory
946391		rainboy	Tapestries (POI13_gob)	C11	10 / 100	2 ms	604 KiB

gob

#include <stdio.h>

#define N	1000
#define INF	1e12
#define eps	1e-12

int sgn(long long a) { return a == 0 ? 0 : (a > 0 ? 1 : -1); }
double min(double a, double b) { return a < b ? a : b; }
double max(double a, double b) { return a > b ? a : b; }

unsigned int X = 12345;

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

typedef long double ld;

long long cross2(int x1, int y1, int x2, int y2) {
	return (long long) x1 * y2 - (long long) x2 * y1;
}

ld cross2_(ld x1, ld y1, ld x2, ld y2) {
	return x1 * y2 - x2 * y1;
}

long long cross(int x0, int y0, int x1, int y1, int x2, int y2) {
	return cross2(x1 - x0, y1 - y0, x2 - x0, y2 - y0);
}

ld cross_(ld x0, ld y0, ld x1, ld y1, ld x2, ld y2) {
	return cross2_(x1 - x0, y1 - y0, x2 - x0, y2 - y0);
}

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

ld dot_(ld x1, ld y1, ld x2, ld y2) {
	return x1 * x2 + y1 * y2;
}

int intersect_(int x1, int y1, int x2, int y2, int x3, int y3, int x4, int y4) {
	return sgn(cross(x1, y1, x2, y2, x3, y3)) * sgn(cross(x1, y1, x2, y2, x4, y4)) < 0 && sgn(cross(x3, y3, x4, y4, x1, y1)) * sgn(cross(x3, y3, x4, y4, x2, y2)) < 0;
}

int xx[N], yy[N]; char tt[N + 1];
int aa[N], bb[N], cc[N];

int compare(int i, int j) {
	int sgni, sgnj;
	long long c;

	sgni = aa[i] < 0 || aa[i] == 0 && bb[i] < 0 ? -1 : 1;
	sgnj = aa[j] < 0 || aa[j] == 0 && bb[j] < 0 ? -1 : 1;
	if (sgni != sgnj)
		return sgni - sgnj;
	c = cross2(aa[i], bb[i], aa[j], bb[j]);
	return c == 0 ? 0 : (c < 0 ? -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;
	}
}

void intersect(int i, int j, ld *x, ld *y) {
	long long c;

	c = cross2(aa[i], bb[i], aa[j], bb[j]);
	*x = (ld) -cross2(cc[i], bb[i], cc[j], bb[j]) / c;
	*y = (ld) -cross2(aa[i], cc[i], aa[j], cc[j]) / c;
}

int check(int i, int j, int k) {
	long long cij, cjk;
	ld x1, y1, x2, y2;

	cij = cross2(aa[i], bb[i], aa[j], bb[j]);
	cjk = cross2(aa[j], bb[j], aa[k], bb[k]);
	if (cij == 0) {
		if (dot(aa[i], bb[i], aa[j], bb[j]) > 0) {
			if ((aa[i] != 0 ? cross2(cc[i], aa[i], cc[j], aa[j]) * sgn(aa[i]) : cross2(cc[i], bb[i], cc[j], bb[j]) * sgn(bb[i])) > 0)
				return 1;
		} else {
			if ((aa[i] != 0 ? cross2(cc[i], aa[i], cc[j], aa[j]) * sgn(aa[i]) : cross2(cc[i], bb[i], cc[j], bb[j]) * sgn(bb[i])) < 0)
				return -1;
		}
	}
	if (cjk == 0) {
		if (dot(aa[k], bb[k], aa[j], bb[j]) > 0) {
			if ((aa[k] != 0 ? cross2(cc[k], aa[k], cc[j], aa[j]) * sgn(aa[k]) : cross2(cc[k], bb[k], cc[j], bb[j]) * sgn(bb[k])) > 0)
				return 1;
		} else {
			if ((aa[k] != 0 ? cross2(cc[k], aa[k], cc[j], aa[j]) * sgn(aa[k]) : cross2(cc[k], bb[k], cc[j], bb[j]) * sgn(bb[k])) < 0)
				return -1;
		}
	}
	if (cij >= 0 || cjk >= 0)
		return 0;
	intersect(i, j, &x1, &y1), intersect(j, k, &x2, &y2);
	if (cross2_(x2 - x1, y2 - y1, aa[j], bb[j]) <= 0)
		return cross2(aa[k], bb[k], aa[i], bb[i]) > 0 ? 1 : -1;
	return 0;
}

int main() {
	int t;

	scanf("%d", &t);
	while (t--) {
		static int ii[N];
		static char s[2];
		int n, n_, head, cnt, h, i, i1, i2, k, tmp;
		long long c;
		ld t, t1, t2;

		scanf("%d", &n);
		for (i = 0; i < n; i++)
			scanf("%d%d", &xx[i], &yy[i]);
		for (i = 0; i < n; i++) {
			scanf("%s", s);
			tt[i] = s[0];
		}
		for (i = 0; i < n; i++) {
			aa[i] = yy[i] - yy[(i + 1) % n];
			bb[i] = xx[(i + 1) % n] - xx[i];
			cc[i] = cross2(xx[i], yy[i], xx[(i + 1) % n], yy[(i + 1) % n]);
		}
		k = 0;
		for (i = 0; i < n; i++)
			if (tt[(i - 1 + n) % n] == 'C' && tt[i] == 'S')
				k++;
		if (k == 0) {
			n_ = 0;
			for (i = 0; i < n; i++)
				if (tt[i] == 'S')
					ii[n_++] = i;
			sort(ii, 0, n_);
			head = cnt = 0;
			for (h = 0; h < n_; h++) {
				i = ii[h];
				if (cnt && (c = check(ii[head + cnt - 1], i, ii[head]))) {
					if (c == -1) {
						printf("NIE\n");
						goto end;
					}
					continue;
				}
				while (cnt >= 2 && (c = check(ii[head + cnt - 2], ii[head + cnt - 1], i))) {
					if (c == -1) {
						printf("NIE\n");
						goto end;
					}
					cnt--;
				}
				while (cnt >= 2 && (c = check(i, ii[head], ii[head + 1]))) {
					if (c == -1) {
						printf("NIE\n");
						goto end;
					}
					head++, cnt--;
				}
				ii[head + cnt++] = i;
			}
			printf(tt[i] == 'C' ? "NIE\n" : "TAK\n");
		} else if (k == 1) {
			i1 = i2 = -1;
			for (i = 0; i < n; i++)
				if (tt[(i - 1 + n) % n] == 'S' && tt[i] == 'C')
					i1 = i;
				else if (tt[(i - 1 + n) % n] == 'C' && tt[i] == 'S')
					i2 = i;
			if ((i1 - i2 + n) % n == 1) {
				printf("NIE\n");
				goto end;
			}
			if (sgn(cross(xx[(i1 - 1 + n) % n], yy[(i1 - 1 + n) % n], xx[i1], yy[i1], xx[i2], yy[i2])) * sgn(cross(xx[i1], yy[i1], xx[i2], yy[i2], xx[(i2 + 1) % n], yy[(i2 + 1) % n])) > 0) {
				printf("NIE\n");
				goto end;
			}
			for (i = 0; i < n; i++)
				if (tt[i] == 'C' && intersect_(xx[i1], yy[i1], xx[i2], yy[i2], xx[i], yy[i], xx[(i + 1) % n], yy[(i + 1) % n])) {
					printf("NIE\n");
					goto end;
				}
			if (cross(xx[(i1 - 1 + n) % n], yy[(i1 - 1 + n) % n], xx[i1], yy[i1], xx[i2], yy[i2]) > 0) {
				if (cross(xx[i1], yy[i1], xx[i2], yy[i2], xx[(i1 + 1) % n], yy[(i1 + 1) % n]) < 0) {
					printf("NIE\n");
					goto end;
				}
			} else {
				if (cross(xx[i1], yy[i1], xx[i2], yy[i2], xx[(i1 + 1) % n], yy[(i1 + 1) % n]) > 0) {
					printf("NIE\n");
					goto end;
				}
				tmp = i1, i1 = i2, i2 = tmp;
			}
			t1 = -INF, t2 = INF;
			for (i = 0; i < n; i++)
				if (tt[i] == 'S') {
					c = cross2(xx[i2] - xx[i1], yy[i2] - yy[i1], xx[(i + 1) % n] - xx[i], yy[(i + 1) % n] - yy[i]);
					if (c == 0) {
						if (cross(xx[i1], yy[i1], xx[i], yy[i], xx[(i + 1) % n], yy[(i + 1) % n]) >= 0) {
							printf("NIE\n");
							goto end;
						}
					} else {
						t = (ld) cross2(xx[i] - xx[i1], yy[i] - yy[i1], xx[(i + 1) % n] - xx[i], yy[(i + 1) % n] - yy[i]) / c;
						if (c > 0)
							t1 = max(t1, t);
						else
							t2 = min(t2, t);
					}
				}
			printf(t1 < t2 ? "TAK\n" : "NIE\n");
		} else {
			printf("?\n");
		}
end:;
	}
	return 0;
}

Compilation message (stderr)

gob.c: In function 'compare':
gob.c:54:33: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   54 |  sgni = aa[i] < 0 || aa[i] == 0 && bb[i] < 0 ? -1 : 1;
      |                      ~~~~~~~~~~~^~~~~~~~~~~~
gob.c:55:33: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   55 |  sgnj = aa[j] < 0 || aa[j] == 0 && bb[j] < 0 ? -1 : 1;
      |                      ~~~~~~~~~~~^~~~~~~~~~~~
gob.c: In function 'main':
gob.c:127:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  127 |  scanf("%d", &t);
      |  ^~~~~~~~~~~~~~~
gob.c:135:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |   scanf("%d", &n);
      |   ^~~~~~~~~~~~~~~
gob.c:137:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |    scanf("%d%d", &xx[i], &yy[i]);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
gob.c:139:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |    scanf("%s", s);
      |    ^~~~~~~~~~~~~~

• Subtask 1: 10 / 100