//#pragma GCC optimize("O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
//#pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const int N = 1e4;
int mod = 1e9 + 7;
int dp[N][N];
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n;
cin >> n;
vector<int> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
int level = 1;
for (int i = 1; i < n; i++) {
for (int j = a[i]; j <= i + 1; j++) {
dp[i][j] = (dp[i - 1][j - 1] + dp[i - 1][j] * j) % mod;
}
dp[i - 1][level]++;
for (int j = 1; j < a[i]; j++) {
dp[i][j] = (dp[i - 1][j - 1] + dp[i - 1][j] * j) % mod;
}
}
int ans = 1;
for (int i = 1; i <= n; i++) {
(ans += dp[n - 1][i]) %= mod;
}
cout << ans;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
508 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
2 ms |
376 KB |
Output is correct |
4 |
Correct |
2 ms |
376 KB |
Output is correct |
5 |
Correct |
2 ms |
376 KB |
Output is correct |
6 |
Correct |
2 ms |
376 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
380 KB |
Output is correct |
2 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
760 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
764 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
4 ms |
2808 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
9 ms |
6364 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
106 ms |
65540 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
103 ms |
65536 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
104 ms |
65536 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |