#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define fr first
#define sc second
#define ARRS ((ll)(2e6+500))
#define MAX ((ll)(1e9+100))
#define MOD ((ll)1e9+7)
#define mi(a,b) a=min((a),(b))
ll n,m,k,p,l,r,q;
ll a[ARRS];
ll slv(ll i,ll c,ll e=0){
if(i==n)return 1;
if(e)
return c*slv(i+1,c,e)+slv(i+1,c+1,e);
else {
ll pas=0;
if(a[i]==c+1){
pas+=c*slv(i+1,c,1);
pas+=slv(i+1,c+1,0);
}
else {
pas+=(a[i]-1)*slv(i+1,c,1);
pas+=slv(i+1,c,0);
}
pas%=MOD;
return pas;
}
}
int main(){
#ifdef KHOKHO
freopen("in.in","r",stdin);
freopen("out.out","w",stdout);
#endif
cin>>n;
for(int i=0; i<n; i++)cin>>a[i];
cout<<slv(0,0,0);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
2 ms |
436 KB |
Output is correct |
4 |
Correct |
2 ms |
492 KB |
Output is correct |
5 |
Correct |
2 ms |
504 KB |
Output is correct |
6 |
Correct |
2 ms |
564 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
640 KB |
Output is correct |
2 |
Correct |
3 ms |
644 KB |
Output is correct |
3 |
Correct |
3 ms |
648 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
648 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1077 ms |
648 KB |
Time limit exceeded |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1057 ms |
672 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1066 ms |
672 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1043 ms |
672 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1074 ms |
1316 KB |
Time limit exceeded |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1075 ms |
1316 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1077 ms |
1380 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |