A Utility that padds zeros in front of the Node , with the given diff
Node paddZeros ( Node sNode , int diff ) { if ( sNode == null ) return null ; Node zHead = new Node ( 0 ) ; diff -- ; Node temp = zHead ; while ( ( diff -- ) != 0 ) { temp . next = new Node ( 0 ) ; temp = temp . next ; } temp . next = sNode ; return zHead ; }