#include <bits/stdc++.h>
#define F first
#define S second
#define PB push_back
#define PF push_front
#define MP make_pair
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int maxn = 1e4 + 10;
const int mod = 1e6 + 7;
ll pd[maxn], dp[3][maxn], par[maxn], a[maxn];
int main() {
int n;
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i];
par[i] = max (par[i - 1], a[i]);
}
for (int i = 1; i <= n; i++)
dp[0][i] = 1;
pd[0] = 1;
for (int i = 1; i <= n; i++) {
int p = i % 2;
for (int j = 1; j <= n; j++) {
dp[p][j] = (1ll * j * dp[p^1][j] + dp[p^1][j + 1]) % mod;
}
pd[i] = dp[p][par[n - i - 1]];
}
ll ans = 0;
for (int i = 1; i <= n; i++) {
ans = (ans + 1ll * (a[i] - 1) * pd[n - i] % mod);
}
cout << (ans + 1) % mod << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
2 ms |
576 KB |
Output is correct |
4 |
Correct |
2 ms |
576 KB |
Output is correct |
5 |
Correct |
2 ms |
576 KB |
Output is correct |
6 |
Correct |
2 ms |
576 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
660 KB |
Output is correct |
2 |
Correct |
2 ms |
660 KB |
Output is correct |
3 |
Correct |
2 ms |
660 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
660 KB |
Output is correct |
2 |
Correct |
2 ms |
660 KB |
Output is correct |
3 |
Correct |
2 ms |
660 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
660 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
660 KB |
Output is correct |
2 |
Correct |
2 ms |
660 KB |
Output is correct |
3 |
Correct |
3 ms |
660 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
660 KB |
Output is correct |
2 |
Correct |
3 ms |
660 KB |
Output is correct |
3 |
Correct |
3 ms |
660 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
660 KB |
Output is correct |
2 |
Correct |
4 ms |
660 KB |
Output is correct |
3 |
Correct |
4 ms |
660 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
212 ms |
1148 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
56 ms |
1148 KB |
Output is correct |
2 |
Correct |
56 ms |
1148 KB |
Output is correct |
3 |
Correct |
62 ms |
1148 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
213 ms |
1180 KB |
Output is correct |
2 |
Correct |
214 ms |
1180 KB |
Output is correct |
3 |
Correct |
216 ms |
1240 KB |
Output is correct |