| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 486431 |
2021-11-11T16:35:01 Z |
rainboy |
Relay (COI16_relay) |
C |
|
2 ms |
204 KB |
#include <stdio.h>
#define N 100000
#define M 100000
long long cross2(int x1, int y1, int x2, int y2) {
return (long long) x1 * y2 - (long long) 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);
}
int xx[N + M], yy[N + M], xxl[N], yyl[N], xxr[N], yyr[N];
int visible(int i1, int i2) {
return cross2(xxr[i1], yyr[i1], xxl[i2], yyl[i2]) <= 0 || cross2(xxr[i2], yyr[i2], xxl[i1], yyl[i1]) <= 0;
}
int main() {
static char good[N];
int n, m, i, i1, i2, j, p, q, k;
scanf("%d", &n);
for (i = 0; i < n; i++)
scanf("%d%d", &xx[i], &yy[i]);
scanf("%d", &m);
for (j = 0; j < m; j++)
scanf("%d%d", &xx[n + j], &yy[n + j]);
for (i1 = 0; i1 < n; i1++) {
for (j = 0; j < m; j++) {
p = (j - 1 + m) % m, q = (j + 1) % m;
if (cross(xx[i1], yy[i1], xx[n + p], yy[n + p], xx[n + j], yy[n + j]) >= 0 && cross(xx[i1], yy[i1], xx[n + q], yy[n + q], xx[n + j], yy[n + j]) > 0)
xxl[i1] = xx[i1] - xx[n + j], yyl[i1] = yy[i1] - yy[n + j];
if (cross(xx[i1], yy[i1], xx[n + q], yy[n + q], xx[n + j], yy[n + j]) <= 0 && cross(xx[i1], yy[i1], xx[n + p], yy[n + p], xx[n + j], yy[n + j]) < 0)
xxr[i1] = xx[n + j] - xx[i1], yyr[i1] = yy[n + j] - yy[i1];
}
}
for (i1 = 1; i1 < n; i1++)
if (visible(0, i1)) {
good[i1] = 1;
for (i2 = 1; i2 < n; i2++)
if (visible(i1, i2))
good[i2] = 1;
}
k = 0;
for (i = 1; i < n; i++)
if (good[i])
k++;
printf("%d\n", k);
return 0;
}
Compilation message
relay.c: In function 'main':
relay.c:24:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
24 | scanf("%d", &n);
| ^~~~~~~~~~~~~~~
relay.c:26:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
26 | scanf("%d%d", &xx[i], &yy[i]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
relay.c:27:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | scanf("%d", &m);
| ^~~~~~~~~~~~~~~
relay.c:29:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
29 | scanf("%d%d", &xx[n + j], &yy[n + j]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
204 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
204 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
204 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
204 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
