#include<bits/stdc++.h>
using namespace std;
int main() {
int n;
cin>>n;
vector<int> t(n);
for(int i=0;i<n;++i) {
cin>>t[i];
}
vector<int> mx(n);
mx[0]=1;
vector<bool> fontos(n);
for(int i=1;i<n;++i) {
mx[i]=max(t[i], mx[i-1]);
fontos[i]=(mx[i]>mx[i-1]);
}
vector<int> dp[2];
dp[0]=vector<int>(10021);
dp[1]=vector<int>(10021);
for(int i=0;i<=n;++i) {
dp[(n-1)&1][i]=1;
}
int ans=t[n-1]-1;
int mod=1e6+7;
for(int i=n-2;i>=0;i--) {
for(int j=0;j<=n;++j) {
dp[i&1][j]=(dp[(i&1)^1][j]*j+dp[(i&1)^1][j+1])%mod;
}
if(fontos[i]) {
ans=(ans+(t[i]-1)*dp[i&1][mx[i]-1])%mod;
}else {
ans=(ans+(t[i]-1)*dp[i&1][mx[i]])%mod;
}
//cerr<<mx[i]<<" "<<dp[i&1][mx[i]]<<"\n";
//ans=(ans+dp[i&1][mx[i]])%mod;
}
cout<<ans+1<<"\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
484 KB |
Output is correct |
3 |
Correct |
3 ms |
484 KB |
Output is correct |
4 |
Correct |
3 ms |
484 KB |
Output is correct |
5 |
Correct |
3 ms |
596 KB |
Output is correct |
6 |
Correct |
2 ms |
596 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
596 KB |
Output is correct |
2 |
Correct |
2 ms |
672 KB |
Output is correct |
3 |
Correct |
2 ms |
672 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
672 KB |
Output is correct |
2 |
Correct |
2 ms |
696 KB |
Output is correct |
3 |
Correct |
2 ms |
696 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
696 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
696 KB |
Output is correct |
2 |
Correct |
2 ms |
696 KB |
Output is correct |
3 |
Correct |
2 ms |
696 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
696 KB |
Output is correct |
2 |
Correct |
4 ms |
696 KB |
Output is correct |
3 |
Correct |
4 ms |
696 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
696 KB |
Output is correct |
2 |
Correct |
7 ms |
696 KB |
Output is correct |
3 |
Correct |
5 ms |
696 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
265 ms |
776 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
77 ms |
776 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
403 ms |
776 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |