#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define pb push_back
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set; ///find_by_order(),order_of_key()
const int N=1e4;
const int mod=1e6+7;
//int dp[N][N]; /// dp[x][y] Number of ways to choose x numbers if the max so far is y
int dp[2][N];
int pref[N];
int add(int a,int b){
a+=b;
if(a>mod)
a-=mod;
return a;
}
int sub(int a,int b)
{
a-=b;
if(a<0)
a+=mod;
return a;
}
int get(int l,int r)
{
if(l==0)
return pref[r];
return sub(pref[r],pref[l-1]);
}
map<pair<int,int>,int> resenja;
set<pair<int,int> > trazi;
int main()
{
int n;
scanf("%i",&n);
/*vector<int> a(n);
for(int i=0;i<n;i++)
scanf("%i",&a[i]);*/
int res=0;
int tr=0;
vector<int> arr(n);
for(int i=0;i<n;i++)
scanf("%i",&arr[i]);
for(int i=0;i<n;i++){
int a=arr[i];
trazi.insert({n-i-1,tr-2});
tr=max(tr,a+1);
}
trazi.insert({N,N});
set<pair<int,int> >::iterator it=trazi.begin();
for(int i=0;i<N;i++){
dp[0][i]=1;
}
while((*it).first<=0)
{
resenja[{(*it).first,(*it).second}]=dp[(*it).first][(*it).second];
it++;
}
for(int n=1;n<N;n++)
{
pref[0]=dp[(n-1)%2][0];
for(int i=1;i<N;i++)
{
pref[i]=add(pref[i-1],dp[(n-1)%2][i]);
}
for(int i=0;i<N-1;i++)
{
dp[n%2][i]=add(((ll)dp[(n-1)%2][i]*(i+1))%mod,dp[(n-1)%2][i+1]);
}
while((*it).first<=n)
{
resenja[{(*it).first,(*it).second}]=dp[((*it).first)%2][(*it).second];
it++;
}
}
tr=0;
for(int i=0;i<n;i++){
int a=arr[i];
// printf("%i %i:%i\n",n-i-1,tr-2,resenja[{n-i-1,tr-2}]);
res=add(res,((ll)(a-1)*resenja[{n-i-1,tr-2}])%mod);
tr=max(tr,a+1);
}
res++;
printf("%i\n",res);
return 0;
}
Compilation message
teams.cpp: In function 'int main()':
teams.cpp:42:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%i",&n);
~~~~~^~~~~~~~~
teams.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%i",&arr[i]);
~~~~~^~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
645 ms |
472 KB |
Output is correct |
2 |
Correct |
644 ms |
552 KB |
Output is correct |
3 |
Correct |
652 ms |
564 KB |
Output is correct |
4 |
Correct |
651 ms |
580 KB |
Output is correct |
5 |
Correct |
643 ms |
584 KB |
Output is correct |
6 |
Correct |
673 ms |
584 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
659 ms |
624 KB |
Output is correct |
2 |
Correct |
646 ms |
660 KB |
Output is correct |
3 |
Correct |
646 ms |
660 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
659 ms |
660 KB |
Output is correct |
2 |
Correct |
678 ms |
660 KB |
Output is correct |
3 |
Correct |
675 ms |
668 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
677 ms |
724 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
645 ms |
728 KB |
Output is correct |
2 |
Correct |
680 ms |
736 KB |
Output is correct |
3 |
Correct |
664 ms |
860 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
663 ms |
860 KB |
Output is correct |
2 |
Correct |
658 ms |
860 KB |
Output is correct |
3 |
Correct |
684 ms |
860 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
652 ms |
860 KB |
Output is correct |
2 |
Correct |
657 ms |
860 KB |
Output is correct |
3 |
Correct |
639 ms |
860 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
660 ms |
1788 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
652 ms |
1788 KB |
Output is correct |
2 |
Correct |
667 ms |
1788 KB |
Output is correct |
3 |
Correct |
658 ms |
1788 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
652 ms |
1828 KB |
Output is correct |
2 |
Correct |
657 ms |
1884 KB |
Output is correct |
3 |
Correct |
664 ms |
1964 KB |
Output is correct |