an array of pointers storing the head nodes of the linked lists
Node * arr [ k ] ; arr [ 0 ] = newNode ( 1 ) ; arr [ 0 ] -> next = newNode ( 3 ) ; arr [ 0 ] -> next -> next = newNode ( 5 ) ; arr [ 0 ] -> next -> next -> next = newNode ( 7 ) ; arr [ 1 ] = newNode ( 2 ) ; arr [ 1 ] -> next = newNode ( 4 ) ; arr [ 1 ] -> next -> next = newNode ( 6 ) ; arr [ 1 ] -> next -> next -> next = newNode ( 8 ) ; arr [ 2 ] = newNode ( 0 ) ; arr [ 2 ] -> next = newNode ( 9 ) ; arr [ 2 ] -> next -> next = newNode ( 10 ) ; arr [ 2 ] -> next -> next -> next = newNode ( 11 ) ;