#include <bits/stdc++.h>
#if defined(__GNUC__)
#pragma GCC optimize ("Ofast")
#endif
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;
const ld eps=1e-7;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod = 1000007;
const int MAXN = 10010, LOG=20;
ll n, m, k, u, v, x, y, t, ans;
int A[MAXN], B[MAXN];
ll dp[2][MAXN];
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
cin>>n;
for (int i=1; i<=n; i++) cin>>A[i], B[i]=max(B[i-1], A[i]);
int a=0, b=1;
for (int j=0; j<=n; j++) dp[a][j]=1;
for (int i=0; i<n; i++){
ans+=dp[a][B[n-i-1]]*(A[n-i]-1);
for (int j=0; j<=n; j++) dp[b][j]=(dp[a][j]*j + dp[a][j+1])%mod;
swap(a, b);
}
ans++;
cout<<ans%mod<<'\n';
return 0;
}
# |
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 |
376 KB |
Output is correct |
4 |
Correct |
2 ms |
380 KB |
Output is correct |
5 |
Correct |
2 ms |
376 KB |
Output is correct |
6 |
Correct |
2 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
380 KB |
Output is correct |
3 |
Correct |
2 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
308 KB |
Output is correct |
3 |
Correct |
2 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
# |
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 |
376 KB |
Output is correct |
# |
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 |
3 ms |
380 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
376 KB |
Output is correct |
2 |
Correct |
4 ms |
376 KB |
Output is correct |
3 |
Correct |
4 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
205 ms |
764 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
55 ms |
532 KB |
Output is correct |
2 |
Correct |
55 ms |
508 KB |
Output is correct |
3 |
Correct |
55 ms |
524 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
211 ms |
648 KB |
Output is correct |
2 |
Correct |
213 ms |
644 KB |
Output is correct |
3 |
Correct |
212 ms |
700 KB |
Output is correct |