HackerEarth's basic programming solutions( Divisible, Seven-Segment Display, A. Movement ) :
Problem 36: Divisible Solution: (in c++) ( please guys before moving to the solution try it yourself at least 3-4 times , if you really wanna become a good coder) #include< bits/stdc++.h > using namespace std ; int main () { long long n , sum = 0 , i ; cin >> n ; long long a [ n ]; for ( i = 0 ; i < n ; i ++) { cin >> a [ i ]; } for ( i = 0 ; i < n / 2 ; i ++) //considering first half elements { while ( a [ i ]>= 10 ) //using this you can find first digit of a number { a [ i ]= a [ i ]/ 10 ; } if ( i % 2 == 0 ) //see note below { sum += a [ i ]; } else { sum +=( a [ i ] *- 1 ); } } for ( i = n / 2 ; i < n ; i ++) //considering next half elements { a [ i ]= a [ i ]% 10 ; //using this you can find the last digit of a number if ( i % 2