/* upsolve after reading analysis */
#include <stdio.h>
#define N 100000
#define M (N * 2)
unsigned int X = 12345;
int abs(int a) { return a > 0 ? a : -a; }
int rand_() {
return (X *= 3) >> 1;
}
void flip(int *xx, int *yy, int n) {
int i, j, tmp;
for (i = 0, j = n - 1; i < j; i++, j--) {
tmp = xx[i], xx[i] = xx[j], xx[j] = tmp;
tmp = yy[i], yy[i] = yy[j], yy[j] = tmp;
}
for (i = 0; i < n; i++)
xx[i] = -xx[i];
}
void rotate(int *xx, int *yy, int n) {
int i, tmp;
for (i = 0; i < n; i++)
tmp = xx[i], xx[i] = -yy[i], yy[i] = tmp;
}
int check1(int *xx1, int *yy1, int *xx2, int *yy2, int n) {
int i_, j_, i, j, x, y;
i_ = -1;
for (i = 0; i < n; i++)
if (i_ == -1 || xx1[i_] > xx1[i] || xx1[i_] == xx1[i] && yy1[i_] > yy1[i])
i_ = i;
j_ = -1;
for (j = 0; j < n; j++)
if (j_ == -1 || xx2[j_] > xx2[j] || xx2[j_] == xx2[j] && yy2[j_] > yy2[j])
j_ = j;
x = xx1[i_] - xx2[j_], y = yy1[i_] - yy2[j_];
for (i = 0; i < n; i++)
if (xx1[(i + i_) % n] - xx2[(i + j_) % n] != x || yy1[(i + i_) % n] - yy2[(i + j_) % n] != y)
return 0;
return 1;
}
int check_(int *xx1, int *yy1, int *xx2, int *yy2, int n) {
int a, b;
for (a = 0; a < 2; a++) {
for (b = 0; b < 4; b++) {
if (check1(xx1, yy1, xx2, yy2, n))
return 1;
rotate(xx2, yy2, n);
}
flip(xx2, yy2, n);
}
return 0;
}
int xx[N], yy[N], n;
int check(int i_, int j_, int x) {
static int xx1[N], yy1[N], xx2[N], yy2[N];
int n1, n2, i;
n1 = 0;
i = (i_ + 1) % n;
while (1) {
if (i == (i_ + 1) % n) {
if (xx[i] != x) {
xx1[n1] = x, yy1[n1] = yy[i], n1++;
xx1[n1] = xx[i], yy1[n1] = yy[i], n1++;
}
} else if (i == j_) {
if (xx[i] != x) {
xx1[n1] = xx[i], yy1[n1] = yy[i], n1++;
xx1[n1] = x, yy1[n1] = yy[i], n1++;
}
break;
} else
xx1[n1] = xx[i], yy1[n1] = yy[i], n1++;
i = (i + 1) % n;
}
n2 = 0;
i = (j_ + 1) % n;
while (1) {
if (i == (j_ + 1) % n) {
if (xx[i] != x) {
xx2[n2] = x, yy2[n2] = yy[i], n2++;
xx2[n2] = xx[i], yy2[n2] = yy[i], n2++;
}
} else if (i == i_) {
if (xx[i] != x) {
xx2[n2] = xx[i], yy2[n2] = yy[i], n2++;
xx2[n2] = x, yy2[n2] = yy[i], n2++;
}
break;
} else
xx2[n2] = xx[i], yy2[n2] = yy[i], n2++;
i = (i + 1) % n;
}
return n1 == n2 && check_(xx1, yy1, xx2, yy2, n1);
}
int xx_[M], kk1[M], kk2[M], tt[M], m;
int iq[1 + M], pq[M], cnt;
int lt(int i, int j) {
return xx_[i] != xx_[j] ? xx_[i] < xx_[j] : tt[i] > tt[j];
}
int p2(int p) {
return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}
void pq_up(int i) {
int p, q, j;
for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
iq[pq[j] = p] = j;
iq[pq[i] = p] = i;
}
void pq_dn(int i) {
int p, q, j;
for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
iq[pq[j] = p] = j;
iq[pq[i] = p] = i;
}
void pq_add(int x, int k1, int k2, int t) {
int i = m++;
xx_[i] = x, kk1[i] = k1, kk2[i] = k2, tt[i] = t;
pq[i] = ++cnt, pq_up(i);
}
int pq_remove_first() {
int i = iq[1], j = iq[cnt--];
if (j != i)
pq[j] = 1, pq_dn(j);
pq[i] = 0;
return i;
}
int zz[1 + N], ll[1 + N], rr[1 + N], kk[1 + N], _, u_, l_, r_;
int node(int k) {
zz[_] = rand_();
ll[_] = rr[_] = 0;
kk[_] = k;
return _++;
}
void split(int u, int k) {
int c;
if (u == 0) {
u_ = l_ = r_ = 0;
return;
}
c = yy[k] - yy[kk[u]];
if (c < 0) {
split(rr[u], k);
rr[u] = l_, l_ = u;
} else if (c > 0) {
split(ll[u], k);
ll[u] = r_, r_ = u;
} else {
u_ = u, l_ = ll[u], r_ = rr[u];
ll[u] = rr[u] = 0;
}
}
int merge(int u, int v) {
if (u == 0)
return v;
if (v == 0)
return u;
if (zz[u] < zz[v]) {
rr[u] = merge(rr[u], v);
return u;
} else {
ll[v] = merge(u, ll[v]);
return v;
}
}
void tr_add(int k) {
split(u_, k);
u_ = merge(merge(l_, node(k)), r_);
}
void tr_remove(int k) {
split(u_, k);
u_ = merge(l_, r_);
}
int tr_lower(int k) {
int u = u_, k_ = -1;
while (u)
if (yy[kk[u]] > yy[k])
k_ = kk[u], u = rr[u];
else
u = ll[u];
return k_;
}
int tr_higher(int k) {
int u = u_, k_ = -1;
while (u)
if (yy[kk[u]] < yy[k])
k_ = kk[u], u = ll[u];
else
u = rr[u];
return k_;
}
long long pp[N * 2];
void add(int i, int j, int x_) {
if (xx[i] < xx[(i + 1) % n] && xx[j] > xx[(j + 1) % n]) {
long long p, x;
int x1, x2, x3, x4;
p = j < i - 1 ? pp[i - 1] - pp[j] : pp[i - 1 + n] - pp[j];
x1 = xx[i], x2 = xx[(j + 1) % n];
if ((x = pp[n - 1] / 2 - p + x1 + x2) % 2 == 0) {
x /= 2;
x3 = xx[(i + 1) % n], x4 = xx[j];
if (x >= x_ && x <= x3 && x <= x4)
pq_add(x, i, j, 0);
}
x_ = 0;
}
}
int main() {
int i, i_, j, r, tmp;
scanf("%d", &n);
i_ = -1;
for (i = 0; i < n; i++) {
scanf("%d%d", &xx[i], &yy[i]);
if (i_ == -1 || xx[i_] > xx[i] || xx[i_] == xx[i] && yy[i_] > yy[i])
i_ = i;
}
if (xx[(i_ + 1) % n] != xx[i_])
for (i = 0, j = n - 1; i < j; i++, j--) {
tmp = xx[i], xx[i] = xx[j], xx[j] = tmp;
tmp = yy[i], yy[i] = yy[j], yy[j] = tmp;
}
for (i = 0; i < n * 2; i++)
pp[i] = abs(xx[i % n] - xx[(i + 1) % n]) + abs(yy[i % n] - yy[(i + 1) % n]);
for (i = 1; i < n * 2; i++)
pp[i] += pp[i - 1];
if (pp[n - 1] % 2 != 0) {
printf("NO\n");
return 0;
}
for (r = 0; r < 2; r++) {
int i_, j_, x_;
m = 0, cnt = 0;
_ = 1, u_ = 0;
for (i = 0; i < n; i++)
if (xx[i] != xx[(i + 1) % n]) {
int x1 = xx[i], x2 = xx[(i + 1) % n];
if (x1 > x2)
tmp = x1, x1 = x2, x2 = tmp;
pq_add(x1, i, i, 1), pq_add(x2, i, i, -1);
}
i_ = -1, j_ = -1, x_ = -1;
while (cnt) {
int h = pq_remove_first(), l, r;
if (tt[h] == 1) {
i = kk1[h], l = tr_lower(i), r = tr_higher(i);
tr_add(i);
if (l != -1)
add(l, i, xx_[h]);
if (r != -1)
add(i, r, xx_[h]);
} else if (tt[h] == -1) {
i = kk1[h], l = tr_lower(i), r = tr_higher(i);
tr_remove(i);
if (l != -1 && r != -1)
add(l, r, xx_[h] + 1);
} else
if (tr_higher(kk1[h]) == kk2[h]) {
i_ = kk1[h], j_ = kk2[h], x_ = xx_[h];
break;
}
}
if (i_ != -1 && j_ != -1 && check(i_, j_, x_)) {
if (r == 0)
printf("%d %d %d %d\n", x_, yy[i_], x_, yy[j_]);
else
printf("%d %d %d %d\n", yy[i_], -x_, yy[j_], -x_);
return 0;
}
rotate(xx, yy, n);
}
printf("NO\n");
return 0;
}
Compilation message
demarcation.c: In function 'check1':
demarcation.c:38:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
38 | if (i_ == -1 || xx1[i_] > xx1[i] || xx1[i_] == xx1[i] && yy1[i_] > yy1[i])
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
demarcation.c:42:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
42 | if (j_ == -1 || xx2[j_] > xx2[j] || xx2[j_] == xx2[j] && yy2[j_] > yy2[j])
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
demarcation.c: In function 'main':
demarcation.c:254:53: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
254 | if (i_ == -1 || xx[i_] > xx[i] || xx[i_] == xx[i] && yy[i_] > yy[i])
| ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
demarcation.c:250:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
250 | scanf("%d", &n);
| ^~~~~~~~~~~~~~~
demarcation.c:253:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
253 | scanf("%d%d", &xx[i], &yy[i]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
1076 KB |
Output is correct |
2 |
Correct |
0 ms |
292 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
7 ms |
980 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
288 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
38 ms |
7648 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
292 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
1 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
0 ms |
340 KB |
Output is correct |
14 |
Correct |
1 ms |
340 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
292 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
0 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
0 ms |
292 KB |
Output is correct |
24 |
Correct |
0 ms |
340 KB |
Output is correct |
25 |
Correct |
0 ms |
340 KB |
Output is correct |
26 |
Correct |
0 ms |
340 KB |
Output is correct |
27 |
Correct |
0 ms |
340 KB |
Output is correct |
28 |
Correct |
0 ms |
340 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
296 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
292 KB |
Output is correct |
5 |
Correct |
0 ms |
296 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
1 ms |
296 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
0 ms |
340 KB |
Output is correct |
11 |
Correct |
0 ms |
340 KB |
Output is correct |
12 |
Correct |
0 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
340 KB |
Output is correct |
15 |
Correct |
0 ms |
292 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
340 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
0 ms |
340 KB |
Output is correct |
24 |
Correct |
0 ms |
340 KB |
Output is correct |
25 |
Correct |
0 ms |
340 KB |
Output is correct |
26 |
Correct |
0 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
1 ms |
340 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
1 ms |
288 KB |
Output is correct |
31 |
Correct |
0 ms |
340 KB |
Output is correct |
32 |
Correct |
2 ms |
468 KB |
Output is correct |
33 |
Correct |
2 ms |
464 KB |
Output is correct |
34 |
Correct |
1 ms |
428 KB |
Output is correct |
35 |
Correct |
1 ms |
428 KB |
Output is correct |
36 |
Correct |
2 ms |
468 KB |
Output is correct |
37 |
Correct |
2 ms |
452 KB |
Output is correct |
38 |
Correct |
1 ms |
468 KB |
Output is correct |
39 |
Correct |
1 ms |
424 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
1108 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
288 KB |
Output is correct |
4 |
Correct |
6 ms |
1092 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
6 |
Correct |
0 ms |
340 KB |
Output is correct |
7 |
Correct |
0 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
340 KB |
Output is correct |
9 |
Correct |
40 ms |
7672 KB |
Output is correct |
10 |
Correct |
1 ms |
340 KB |
Output is correct |
11 |
Correct |
1 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
292 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
1 ms |
340 KB |
Output is correct |
15 |
Correct |
1 ms |
292 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
0 ms |
340 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
0 ms |
340 KB |
Output is correct |
20 |
Correct |
0 ms |
340 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
292 KB |
Output is correct |
24 |
Correct |
1 ms |
292 KB |
Output is correct |
25 |
Correct |
1 ms |
292 KB |
Output is correct |
26 |
Correct |
0 ms |
292 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
0 ms |
340 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
0 ms |
340 KB |
Output is correct |
31 |
Correct |
0 ms |
292 KB |
Output is correct |
32 |
Correct |
1 ms |
340 KB |
Output is correct |
33 |
Correct |
0 ms |
340 KB |
Output is correct |
34 |
Correct |
0 ms |
340 KB |
Output is correct |
35 |
Correct |
2 ms |
468 KB |
Output is correct |
36 |
Correct |
2 ms |
464 KB |
Output is correct |
37 |
Correct |
1 ms |
468 KB |
Output is correct |
38 |
Correct |
1 ms |
340 KB |
Output is correct |
39 |
Correct |
2 ms |
468 KB |
Output is correct |
40 |
Correct |
1 ms |
468 KB |
Output is correct |
41 |
Correct |
2 ms |
468 KB |
Output is correct |
42 |
Correct |
1 ms |
340 KB |
Output is correct |
43 |
Correct |
2 ms |
468 KB |
Output is correct |
44 |
Correct |
43 ms |
3228 KB |
Output is correct |
45 |
Correct |
57 ms |
4152 KB |
Output is correct |
46 |
Correct |
26 ms |
2672 KB |
Output is correct |
47 |
Correct |
16 ms |
1624 KB |
Output is correct |
48 |
Correct |
17 ms |
1908 KB |
Output is correct |
49 |
Correct |
89 ms |
7256 KB |
Output is correct |
50 |
Correct |
41 ms |
6256 KB |
Output is correct |
51 |
Correct |
58 ms |
7896 KB |
Output is correct |
52 |
Correct |
145 ms |
8460 KB |
Output is correct |
53 |
Correct |
120 ms |
6812 KB |
Output is correct |
54 |
Correct |
105 ms |
6824 KB |
Output is correct |
55 |
Correct |
50 ms |
3112 KB |
Output is correct |
56 |
Correct |
47 ms |
7416 KB |
Output is correct |
57 |
Correct |
127 ms |
7720 KB |
Output is correct |
58 |
Correct |
103 ms |
7116 KB |
Output is correct |
59 |
Correct |
98 ms |
7988 KB |
Output is correct |
60 |
Correct |
35 ms |
3404 KB |
Output is correct |
61 |
Correct |
8 ms |
1492 KB |
Output is correct |
62 |
Correct |
13 ms |
2220 KB |
Output is correct |
63 |
Correct |
21 ms |
2884 KB |
Output is correct |
64 |
Correct |
18 ms |
2972 KB |
Output is correct |
65 |
Correct |
39 ms |
2764 KB |
Output is correct |
66 |
Correct |
37 ms |
6532 KB |
Output is correct |