Function main

Hackerrank_problems/Sam and substrings/solution.cpp:23–50

*/

int main()
{
   fastio // faster I/O
   // take input as a string due to contraints
   string s;
   cin>>s;
   int n = s.size();
   // initializing dp states
   ll* dp =new ll[n];
   // initializing dp[0] as the first digit
   dp[0]=int(s[0]-'0');
   for(int i=1;i<n;i++)
   {
       int key = int(s[i]-'0');
       // recurrence step
       dp[i]= dp[i-1]*10 + key*(i+1);
       dp[i]%=mod;
   }
   ll sum=0;
   // summing dp[i] states from 0 to n-1
   for(int i=0;i<n;i++)
   {
       sum+=dp[i];
       sum%=mod;
   }
   // print answer
   cout<<sum<<endl;
}