#include <stdio.h>
#define N 200000
#define INF 0x3f3f3f3f
int min(int a, int b) { return a < b ? a : b; }
long long max(long long a, long long b) { return a > b ? a : b; }
long long xx[N], yy[N];
long long cross(int i, int j, int k) {
return (xx[j] - xx[i]) * (yy[k] - yy[i]) - (xx[k] - xx[i]) * (yy[j] - yy[i]);
}
long long eval(int i, int x) {
return xx[i] * x + yy[i];
}
long long ans;
void solve_batch(int *aa, int *bb, int *ll, int *rr, int *jj, int m) {
static int qu[N];
int h, i, j, l_, r_, cnt;
l_ = ll[jj[m - 1]], r_ = rr[jj[0]];
cnt = 0;
for (j = 0, i = l_, h = -1; j < m; j++) {
int j_ = jj[j];
while (i < rr[j_]) {
xx[i] = aa[i], yy[i] = (long long) (-i + 1) * aa[i];
if (cnt && xx[qu[cnt - 1]] == xx[i]) {
if (yy[qu[cnt - 1]] < yy[i]) {
cnt--;
while (cnt >= 2 && cross(qu[cnt - 2], qu[cnt - 1], i) >= 0)
cnt--;
qu[cnt++] = i;
}
} else {
while (cnt >= 2 && cross(qu[cnt - 2], qu[cnt - 1], i) >= 0)
cnt--;
qu[cnt++] = i;
}
i++;
}
if (h < 0)
h = 0;
if (h >= cnt)
h = cnt - 1;
while (h + 1 < cnt && eval(qu[h], j_) < eval(qu[h + 1], j_))
h++;
while (h > 0 && eval(qu[h], j_) < eval(qu[h - 1], j_))
h--;
ans = max(ans, eval(qu[h], j_) * bb[j_]);
}
cnt = 0;
for (j = m - 1, i = r_ - 1, h = -1; j >= 0; j--) {
int j_ = jj[j];
while (i >= ll[j_]) {
xx[i] = aa[i], yy[i] = (long long) (-i + 1) * aa[i];
if (cnt && xx[qu[cnt - 1]] == xx[i]) {
if (yy[qu[cnt - 1]] < yy[i]) {
cnt--;
while (cnt >= 2 && cross(qu[cnt - 2], qu[cnt - 1], i) <= 0)
cnt--;
qu[cnt++] = i;
}
} else {
while (cnt >= 2 && cross(qu[cnt - 2], qu[cnt - 1], i) <= 0)
cnt--;
qu[cnt++] = i;
}
i--;
}
if (h < 0)
h = 0;
if (h >= cnt)
h = cnt - 1;
while (h + 1 < cnt && eval(qu[h], j_) < eval(qu[h + 1], j_))
h++;
while (h > 0 && eval(qu[h], j_) < eval(qu[h - 1], j_))
h--;
ans = max(ans, eval(qu[h], j_) * bb[j_]);
}
}
void solve(int *aa, int *bb, int l, int r) {
static int qqa[N], qqb[N], ppa[N], ppb[N], iia[N], iib[N], jj[N];
int m = (l + r) / 2, i, j, cnt;
if (r - l == 1) {
ans = max(ans, (long long) aa[l] * bb[l]);
return;
}
solve(aa, bb, l, m), solve(aa, bb, m, r);
for (i = m - 1; i >= l; i--)
qqa[i] = min(i + 1 == m ? INF : qqa[i + 1], aa[i]);
for (i = m - 1; i >= l; i--)
qqb[i] = min(i + 1 == m ? INF : qqb[i + 1], bb[i]);
for (j = m; j < r; j++)
ppa[j] = min(j == m ? INF : ppa[j - 1], aa[j]);
for (j = m; j < r; j++)
ppb[j] = min(j == m ? INF : ppb[j - 1], bb[j]);
for (i = l, j = r - 1; i < m; i++) {
while (j >= m && (qqa[i] > ppa[j] || qqb[i] > ppb[j]))
j--;
if (j >= m)
ans = max(ans, (long long) qqa[i] * qqb[i] * (j - i + 1));
}
for (i = l, j = r - 1; j >= m; j--) {
while (i < m && ppa[j] > qqa[i])
i++;
iia[j] = i;
}
for (i = l, j = r - 1; j >= m; j--) {
while (i < m && ppb[j] > qqb[i])
i++;
iib[j] = i;
}
for (j = r - 1; j >= m; j--) {
i = max(iia[j], iib[j]);
if (i < m)
ans = max(ans, (long long) ppa[j] * ppb[j] * (j - i + 1));
}
cnt = 0;
for (j = r - 1; j >= m; j--)
if (iia[j] < iib[j]) {
if (cnt > 0 && iib[jj[cnt - 1]] < iia[j])
solve_batch(qqb, ppa, iia, iib, jj, cnt), cnt = 0;
jj[cnt++] = j;
}
if (cnt > 0)
solve_batch(qqb, ppa, iia, iib, jj, cnt), cnt = 0;
cnt = 0;
for (j = r - 1; j >= m; j--)
if (iib[j] < iia[j]) {
if (cnt > 0 && iia[jj[cnt - 1]] < iib[j])
solve_batch(qqa, ppb, iib, iia, jj, cnt), cnt = 0;
jj[cnt++] = j;
}
if (cnt > 0)
solve_batch(qqa, ppb, iib, iia, jj, cnt), cnt = 0;
}
int main() {
static int aa[N], bb[N];
int n, i;
scanf("%d", &n);
for (i = 0; i < n; i++)
scanf("%d%d", &aa[i], &bb[i]);
ans = 0;
solve(aa, bb, 0, n);
printf("%lld\n", ans);
return 0;
}
Compilation message
histogram.c: In function 'main':
histogram.c:150:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
150 | scanf("%d", &n);
| ^~~~~~~~~~~~~~~
histogram.c:152:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
152 | scanf("%d%d", &aa[i], &bb[i]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
332 KB |
Output is correct |
| 2 |
Correct |
2 ms |
332 KB |
Output is correct |
| 3 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
332 KB |
Output is correct |
| 2 |
Correct |
2 ms |
332 KB |
Output is correct |
| 3 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
