/**
* author: NimaAryan
* created: 2023-10-26 10:49:24
**/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "algo/debug.h"
#endif
using i64 = long long;
constexpr i64 M = 1E9 + 7;
void add(i64& x, i64 y) {
if ((x += y) >= M) {
x -= M;
}
}
struct Info {
int max_lis;
i64 sum = 0;
};
Info operator+(Info a, Info b) {
if (a.max_lis == b.max_lis) {
add(a.sum, b.sum);
return a;
}
return a.max_lis > b.max_lis ? a : b;
}
struct SegmentTree {
vector<Info> info;
int n;
SegmentTree(int n) : n(n) {
info.assign(4 << __lg(n), Info());
}
void modify(int p, int l, int r, int x, Info v) {
if (r - l == 1) {
info[p] = info[p] + v;
return;
}
int m = (l + r) / 2;
if (x < m) {
modify(2 * p, l, m, x, v);
} else {
modify(2 * p + 1, m, r, x, v);
}
info[p] = info[2 * p] + info[2 * p + 1];
}
void modify(int x, Info v) {
modify(1, 0, n, x, v);
}
Info query(int p, int l, int r, int lx, int rx) {
if (l >= rx || r <= lx) {
return Info();
}
if (l >= lx && r <= rx) {
return info[p];
}
int m = (l + r) / 2;
return query(2 * p, l, m, lx, rx) +
query(2 * p + 1, m, r, lx, rx);
}
Info query(int lx, int rx) {
return query(1, 0, n, lx, rx);
}
};
auto LIS(vector<int> A) {
auto B = A;
sort(B.begin(), B.end());
int n = A.size();
for (int i = 0; i < n; ++i) {
A[i] = lower_bound(B.begin(), B.end(), A[i]) - B.begin();
}
SegmentTree seg(n + 1);
seg.modify(n, Info{0, 1});
vector<int> lis(n);
vector<i64> cnt(n);
for (int i = n - 1; i >= 0; --i) {
Info best = seg.query(A[i] + 1, n + 1);
lis[i] = best.max_lis + 1;
cnt[i] = best.sum;
seg.modify(A[i], Info{lis[i], cnt[i]});
}
return pair(lis, cnt);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N;
cin >> N;
vector<int> A(N);
for (int i = 0; i < N; ++i) {
cin >> A[i];
}
auto [lis, cnt_lis] = LIS(A);
for (int i = 0; i < N; ++i) {
A[i] *= -1;
}
auto [lds, cnt_lds] = LIS(A);
int best = 0;
for (int i = 0; i < N; ++i) {
best = max(best, lis[i] + lds[i] - 1);
}
i64 pow2 = 1;
int p = 0;
while (p < N - best) {
pow2 = (pow2 * 2) % M;
p += 1;
}
i64 cnt = 0;
for (int i = 0; i < N; ++i) {
if (lis[i] + lds[i] - 1 == best) {
add(cnt, cnt_lis[i] * cnt_lds[i] % M * pow2 % M);
}
}
cout << best << " " << cnt << "\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
600 KB |
Output is correct |
11 |
Correct |
128 ms |
16020 KB |
Output is correct |
12 |
Correct |
108 ms |
15056 KB |
Output is correct |
13 |
Correct |
97 ms |
10400 KB |
Output is correct |
14 |
Correct |
134 ms |
15080 KB |
Output is correct |
15 |
Correct |
174 ms |
16680 KB |
Output is correct |
16 |
Correct |
212 ms |
17828 KB |
Output is correct |
17 |
Correct |
162 ms |
17840 KB |
Output is correct |
18 |
Correct |
160 ms |
18016 KB |
Output is correct |
19 |
Correct |
150 ms |
17888 KB |
Output is correct |
20 |
Correct |
154 ms |
17916 KB |
Output is correct |