#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define pb push_back
#define x first
#define y second
#define pii pair<int, int>
#define p3i pair<pii, int>
#define pll pair<ll, ll>
#define p3l pair<pll, ll>
#define lseg L, (L+R)/2, N*2+1
#define rseg (L+R)/2+1, R, N*2+2
#define ub upper_bound
#define lb lower_bound
#define pq priority_queue
#define MN 1000007
#define fox(k, x) for (int k=0; k<x; ++k)
#define fox1(k, x) for (int k=1; k<=x; ++k)
#define foxr(k, x) for (int k=x-1; k>=0; --k)
#define fox1r(k, x) for (int k=x; k>0; --k)
#define ms multiset
#define flood(x) memset(x, 0x3f3f3f3f, sizeof x)
#define drain(x) memset(x, 0, sizeof x)
#define rng() (rand() >> 3)*rand()
int n, a[10005], b[10005], ans=1;
vector<int> dp[10001];
void dfs(int N, int T){
//if (T>1001) return;
if (T>b[N]) return;
if (dp[N][T]!=0) return;
if (N==n){
dp[N][T]=1;
return;
}
dfs(N+1, T);
dfs(N+1, T+1);
dp[N][T]+=(1LL*T*dp[N+1][T])%MN;
dp[N][T]+=dp[N+1][T+1];
dp[N][T]%=MN;
}
void dfs2(int N, int T){
if (N==n) return;
dfs(N+1, T);
ans=(1LL*dp[N+1][T]*(a[N]-1)+ans)%MN;
dfs2(N+1, max(a[N], T));
}
int main(){
cin >> n;
fox(l, n+1) dp[l]=vector<int>(l+1, 0);
fox(l, n){
cin >> a[l];
}
fox1(l, n) b[l]=max(b[l-1], a[l]);
dfs2(0, 0);
cout << ans;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2328 KB |
Output is correct |
2 |
Correct |
0 ms |
2328 KB |
Output is correct |
3 |
Correct |
0 ms |
2328 KB |
Output is correct |
4 |
Correct |
0 ms |
2328 KB |
Output is correct |
5 |
Correct |
0 ms |
2328 KB |
Output is correct |
6 |
Correct |
0 ms |
2328 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2328 KB |
Output is correct |
2 |
Incorrect |
0 ms |
2328 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
2328 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
2328 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
2328 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
2856 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
4308 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Memory limit exceeded |
26 ms |
65536 KB |
Memory limit exceeded |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
26 ms |
51320 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Memory limit exceeded |
13 ms |
65536 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |