question: public Map < Integer , Integer > popMissing ( ) { HashMap < Integer , Integer > map = new HashMap < > ( ) ; for ( int i = 0 ; i < missingBlocks . length ; i ++ ) { int count = missingBlocks [ i ] ; if ( count > 0 ) { map . put ( i , count ) ; } } Arrays . fill ( missingBlocks , 0 ) ; return map ; }
target:  Gets the list of missing blocks and clears the list for the next operation.