Initialize two variables
long l = ( long ) pow ( 10 , N - 1 ) , r = ( long ) pow ( 10 , N ) - 1 ; if ( l == 1 ) l = 0 ; long ans = 0 ; for ( long i = l ; i <= r ; i ++ ) { int even_sum = 0 , odd_sum = 0 ; long itr = 0 , num = reverse ( i ) ;