// Nurstan Duisengaliev(REALBOY)
// Respa Gold_2022
// IZHO GOLD_2022
// IOI_2022
/*#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("O3")*/
#include <bits/stdc++.h>
#define ll long long
#define all(x) x.begin(), x.end()
#define in insert
#define mp make_pair
#define F first
#define S second
#define ppf pop_front
#define pb push_back
#define ppb pop_back
#define pf push_front
#define pii pair <ll, ll>
#define boost() ios_base::sync_with_stdio(0), cin.tie(0)
#define sz(x) (int)x.size()
#define int ll
using namespace std;
const int N = (int)2e5 + 123;
const int mod = (int)1e9 + 7;
const ll INF = (ll)1e18 + 1;
int n, a[N], b[N];
ll ans = 0;
void Case1 (int l, int mid, int r) {
int pos = mid, minia = mod, minib = mod;
for (int i = mid; i >= l; i --) {
minia = min (minia, a[i]);
minib = min (minib, b[i]);
while (pos < r && a[pos + 1] >= minia && b[pos + 1] >= minib) pos ++;
ans = max (ans, minia * 1ll * minib * 1ll * (pos - i + 1));
}
}
vector <pii> d[N * 4];
vector <pii> line;
int ok[N * 4];
int intercept (pii a, pii b, pii c, pii d) {
return (b.S - a.S) * (c.F - d.F) - (d.S - c.S) * (a.F - b.F);
}
bool check (pii it, int v) {
if (it.F == d[v].back().F) return 1;
else {
return intercept (d[v][sz (d[v]) - 1], it, d[v][sz (d[v]) - 1], d[v][sz (d[v]) - 2]) >= 0;
}
}
void Build (int v, int l, int r) {
ok[v] = 0;
if (l == r) {
d[v].pb (line[l]);
return;
}
int mid = l + r >> 1;
Build (v * 2, l, mid);
Build (v * 2 + 1, mid + 1, r);
d[v] = d[v * 2];
for (auto it : d[v * 2 + 1]) {
while (sz (d[v]) >= 2 && intercept (d[v][sz (d[v]) - 1], it, d[v][sz (d[v]) - 1], d[v][sz (d[v]) - 2]) >= 0) {
d[v].ppb ();
}
d[v].pb (it);
}
}
void Build_CHT (int l, int mid, int r) {
line.clear ();
int minib = mod;
for (int i = mid + 1; i <= r; i ++) {
minib = min (minib, b[i]);
line.pb (mp (minib, minib * i));
}
for (int i = 1; i <= sz (line) * 4; i ++) d[i].clear ();
Build (1, 0, sz (line) - 1);
}
ll Val (ll x, pii k) {
return x * k.F + k.S;
}
ll Get (int v, int l, int r, int nl, int nr, int x) {
if (nl > r || l > nr) return 0ll;
if (nl <= l && r <= nr) {
while (ok[v] + 1 < sz (d[v]) && Val (x, d[v][ok[v] + 1]) >= Val (x, d[v][ok[v]])) ok[v] ++;
return Val (x, d[v][ok[v]]);
}
int mid = l + r >> 1;
return max (Get (v * 2, l, mid, nl, nr, x), Get (v * 2 + 1, mid + 1, r, nl, nr, x));
}
void Case2 (int l, int mid, int r) {
int minia = mod, minib = mod, minio = mod, sl = mid, sr = mid;
vector <pii> interval;
for (int i = mid; i >= l; i --) {
minia = min (minia, a[i]);
minib = min (minib, b[i]);
while (sr < r && a[sr + 1] >= minia) sr ++;
while (sl <= r && minio > minib) {
sl ++;
minio = min (minio, b[sl]);
}
// sl....sr
interval.pb (mp (sl - mid - 1, sr - mid - 1));
}
Build_CHT (l, mid, r);
minia = mod;
for (int i = mid; i >= l; i --) {
minia = min (minia, a[i]);
// interval[mid - i]
int L = interval[mid - i].F, R = interval[mid - i].S;
if (L >= 0 && L <= R) ans = max (ans, minia * 1ll * Get (1, 0, sz (line) - 1, L, R, 1 - i));
}
}
void calc (int l, int r, int t) {
if (l > r) return;
if (l == r) {
ans = max (ans, a[l] * 1ll * b[l]);
return;
}
int mid = (l + r - t) / 2;
Case1 (l, mid, r);
Case2 (l, mid, r);
calc (l, mid, t);
calc (mid + 1, r, t);
}
void solve () {
cin >> n;
for (int i = 1; i <= n; i ++) {
cin >> a[i] >> b[i];
}
calc (1, n, 0);
reverse (a + 1, a + n + 1);
reverse (b + 1, b + n + 1);
calc (1, n, 1);
cout << ans;
}
main () {
// freopen (".in", "r", stdin);
// freopen (".out", "w", stdout);
boost ();
int TT = 1;
// cin >> TT;
while (TT --) {
solve ();
}
return 0;
}
Compilation message
histogram.cpp: In function 'void Build(long long int, long long int, long long int)':
histogram.cpp:61:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
61 | int mid = l + r >> 1;
| ~~^~~
histogram.cpp: In function 'long long int Get(long long int, long long int, long long int, long long int, long long int, long long int)':
histogram.cpp:91:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
91 | int mid = l + r >> 1;
| ~~^~~
histogram.cpp: At global scope:
histogram.cpp:141:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
141 | main () {
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
13 ms |
19276 KB |
Output is correct |
| 2 |
Correct |
12 ms |
19264 KB |
Output is correct |
| 3 |
Correct |
13 ms |
19268 KB |
Output is correct |
| 4 |
Incorrect |
22 ms |
19264 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
13 ms |
19276 KB |
Output is correct |
| 2 |
Correct |
12 ms |
19264 KB |
Output is correct |
| 3 |
Correct |
13 ms |
19268 KB |
Output is correct |
| 4 |
Incorrect |
22 ms |
19264 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
