an array of pointers storing the head nodes of the linked lists
arr = [ None for i in range ( k ) ] NEW_LINE arr [ 0 ] = Node ( 1 ) NEW_LINE arr [ 0 ] . next = Node ( 3 ) NEW_LINE arr [ 0 ] . next . next = Node ( 5 ) NEW_LINE arr [ 0 ] . next . next . next = Node ( 7 ) NEW_LINE arr [ 1 ] = Node ( 2 ) NEW_LINE arr [ 1 ] . next = Node ( 4 ) NEW_LINE arr [ 1 ] . next . next = Node ( 6 ) NEW_LINE arr [ 1 ] . next . next . next = Node ( 8 ) NEW_LINE arr [ 2 ] = Node ( 0 ) NEW_LINE arr [ 2 ] . next = Node ( 9 ) NEW_LINE arr [ 2 ] . next . next = Node ( 10 ) NEW_LINE arr [ 2 ] . next . next . next = Node ( 11 ) NEW_LINE