#include <stdio.h>
#define N 2000
#define M (N * (N - 1))
#define N_ (1 << 11) /* N_ = pow2(ceil(log2(N))) */
long long max(long long a, long long b) { return a > b ? a : b; }
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;
}
int xx[N], yy[N], ww[N], ii[N], idx[N], n;
int uu[M], vv[M], xx_[M], yy_[M], hh[M], m;
int compare_h(int h1, int h2) {
int x1 = xx_[h1], y1 = yy_[h1], s1 = x1 < 0 || x1 == 0 && y1 < 0 ? -1 : 1;
int x2 = xx_[h2], y2 = yy_[h2], s2 = x2 < 0 || x2 == 0 && y2 < 0 ? -1 : 1;
long long c;
if (s1 != s2)
return s1 - s2;
c = cross(x1, y1, x2, y2);
return c == 0 ? 0 : (c < 0 ? -1 : 1);
}
int x_, y_;
int compare_i(int i, int j) {
long long c, d;
c = cross(x_, y_, xx[i] - xx[j], yy[i] - yy[j]);
if (c != 0)
return c < 0 ? -1 : 1;
d = dot(x_, y_, xx[i] - xx[j], yy[i] - yy[j]);
return d == 0 ? 0 : (d < 0 ? -1 : 1);
}
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) {
int c = compare_h(hh[j], h);
if (c == 0)
j++;
else if (c < 0) {
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;
}
}
long long st[N_ * 2], ss[N_ * 2], pp[N_ * 2], qq[N_ * 2]; int n_;
void pul(int i) {
int l = i << 1, r = l | 1;
ss[i] = ss[l] + ss[r];
pp[i] = max(pp[l], ss[l] + pp[r]);
qq[i] = max(qq[l] + ss[r], qq[r]);
st[i] = max(max(st[l], st[r]), qq[l] + pp[r]);
}
void build() {
int i;
n_ = 1;
while (n_ < n)
n_ <<= 1;
for (i = 0; i < n; i++) {
int w = ww[ii[i]];
ss[n_ + i] = w, st[n_ + i] = pp[n_ + i] = qq[n_ + i] = max(w, 0);
}
for (i = n_ - 1; i > 0; i--)
pul(i);
}
void update(int i, int x) {
i += n_;
ss[i] = x, st[i] = pp[i] = qq[i] = max(x, 0);
while (i > 1)
pul(i >>= 1);
}
void bubble(int i) {
int h, j;
h = idx[i];
while (h + 1 < n && compare_i(i, j = ii[h + 1]) > 0) {
ii[idx[j] = h] = j, ii[idx[i] = h + 1] = i;
update(h, ww[j]), update(h + 1, ww[i]);
h++;
}
while (h > 0 && compare_i(i, j = ii[h - 1]) < 0) {
ii[idx[j] = h] = j, ii[idx[i] = h - 1] = i;
update(h, ww[j]), update(h - 1, ww[i]);
h--;
}
}
int main() {
int h, h_, i, j;
long long ans;
scanf("%d", &n);
for (i = 0; i < n; i++)
scanf("%d%d%d", &xx[i], &yy[i], &ww[i]);
m = 0;
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
if (i != j)
uu[m] = i, vv[m] = j, xx_[m] = xx[j] - xx[i], yy_[m] = yy[j] - yy[i], m++;
for (h = 0; h < m; h++)
hh[h] = h;
sort(hh, 0, m);
for (i = 0; i < n; i++)
ii[idx[i] = i] = i;
build();
x_ = xx_[hh[0]], y_ = yy_[hh[0]];
for (i = 0; i < n; i++)
bubble(i);
ans = 0;
for (h = 0; h < m; h++) {
h_ = hh[h], x_ = xx_[h_], y_ = yy_[h_];
bubble(uu[h_]), bubble(vv[h_]);
if (h + 1 == m || compare_h(h_, hh[h + 1]) != 0)
ans = max(ans, st[1]);
}
printf("%lld\n", ans);
return 0;
}
Compilation message
bulldozer.c: In function 'compare_h':
bulldozer.c:27:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
27 | int x1 = xx_[h1], y1 = yy_[h1], s1 = x1 < 0 || x1 == 0 && y1 < 0 ? -1 : 1;
| ~~~~~~~~^~~~~~~~~
bulldozer.c:28:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
28 | int x2 = xx_[h2], y2 = yy_[h2], s2 = x2 < 0 || x2 == 0 && y2 < 0 ? -1 : 1;
| ~~~~~~~~^~~~~~~~~
bulldozer.c: In function 'main':
bulldozer.c:124:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
124 | scanf("%d", &n);
| ^~~~~~~~~~~~~~~
bulldozer.c:126:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
126 | scanf("%d%d%d", &xx[i], &yy[i], &ww[i]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
548 KB |
Output is correct |
| 2 |
Correct |
2 ms |
548 KB |
Output is correct |
| 3 |
Correct |
3 ms |
468 KB |
Output is correct |
| 4 |
Correct |
2 ms |
468 KB |
Output is correct |
| 5 |
Correct |
3 ms |
544 KB |
Output is correct |
| 6 |
Correct |
2 ms |
468 KB |
Output is correct |
| 7 |
Correct |
2 ms |
468 KB |
Output is correct |
| 8 |
Correct |
2 ms |
468 KB |
Output is correct |
| 9 |
Correct |
2 ms |
468 KB |
Output is correct |
| 10 |
Correct |
2 ms |
512 KB |
Output is correct |
| 11 |
Correct |
1 ms |
340 KB |
Output is correct |
| 12 |
Incorrect |
1 ms |
284 KB |
Output isn't correct |
| 13 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
468 KB |
Output is correct |
| 2 |
Correct |
6 ms |
468 KB |
Output is correct |
| 3 |
Correct |
5 ms |
468 KB |
Output is correct |
| 4 |
Incorrect |
6 ms |
468 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
468 KB |
Output is correct |
| 2 |
Correct |
6 ms |
468 KB |
Output is correct |
| 3 |
Correct |
5 ms |
468 KB |
Output is correct |
| 4 |
Incorrect |
6 ms |
468 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
468 KB |
Output is correct |
| 2 |
Correct |
6 ms |
468 KB |
Output is correct |
| 3 |
Correct |
5 ms |
468 KB |
Output is correct |
| 4 |
Incorrect |
6 ms |
468 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
548 KB |
Output is correct |
| 2 |
Correct |
2 ms |
548 KB |
Output is correct |
| 3 |
Correct |
3 ms |
468 KB |
Output is correct |
| 4 |
Correct |
2 ms |
468 KB |
Output is correct |
| 5 |
Correct |
3 ms |
544 KB |
Output is correct |
| 6 |
Correct |
2 ms |
468 KB |
Output is correct |
| 7 |
Correct |
2 ms |
468 KB |
Output is correct |
| 8 |
Correct |
2 ms |
468 KB |
Output is correct |
| 9 |
Correct |
2 ms |
468 KB |
Output is correct |
| 10 |
Correct |
2 ms |
512 KB |
Output is correct |
| 11 |
Correct |
1 ms |
340 KB |
Output is correct |
| 12 |
Incorrect |
1 ms |
284 KB |
Output isn't correct |
| 13 |
Halted |
0 ms |
0 KB |
- |
