Modify the following code to allow strings of various lengths to be sorted without any additional data structures used to store the data. The code below only allows fixed length. Thanks!

import java.util.ArrayList; import java.util.List; import java.util.Arrays; import java.util.Random; public class RadixSort { /* * Radix sort an array of Strings * Assume all are all ASCII * Assume all have same length */ @SuppressWarnings("unchecked") public static void radixSortA( String [ ] arr, int stringLen ) { final int BUCKETS = 256; ArrayList [ ] buckets = new ArrayList[ BUCKETS ]; for( int i = 0; i < BUCKETS; i++ ) buckets[ i ] = new ArrayList<>( ); for( int pos = stringLen - 1; pos >= 0; pos-- ) { for( String s : arr ) buckets[ s.charAt( pos ) ].add( s ); int idx = 0; for( ArrayList thisBucket : buckets ) { for( String s : thisBucket ) arr[ idx++ ] = s; thisBucket.clear( ); } } } /* * Counting radix sort an array of Strings * Assume all are all ASCII * Assume all have same length */ public static void countingRadixSort( String [ ] arr, int stringLen ) { final int BUCKETS = 256; int N = arr.length; String [ ] buffer = new String[ N ]; String [ ] in = arr; String [ ] out = buffer; for( int pos = stringLen - 1; pos >= 0; pos-- ) { int[ ] count = new int [ BUCKETS + 1 ]; for( int i = 0; i < N; i++ ) count[ in[ i ].charAt( pos ) + 1 ]++; for( int b = 1; b <= BUCKETS; b++ ) count[ b ] += count[ b - 1 ]; for( int i = 0; i < N; i++ ) out[ count[ in[ i ].charAt( pos ) ]++ ] = in[ i ]; // swap in and out roles String [ ] tmp = in; in = out; out = tmp; } // if odd number of passes, in is buffer, out is arr; so copy back if( stringLen % 2 == 1 ) for( int i = 0; i < arr.length; i++ ) out[ i ] = in[ i ]; } /* * Radix sort an array of Strings * Assume all are all ASCII * Assume all have length bounded by maxLen */ @SuppressWarnings("unchecked") public static void radixSort( String [ ] arr, int maxLen ) { final int BUCKETS = 256; ArrayList [ ] wordsByLength = new ArrayList[ maxLen + 1 ]; ArrayList [ ] buckets = new ArrayList[ BUCKETS ]; for( int i = 0; i < wordsByLength.length; i++ ) wordsByLength[ i ] = new ArrayList<>( ); for( int i = 0; i < BUCKETS; i++ ) buckets[ i ] = new ArrayList<>( ); for( String s : arr ) wordsByLength[ s.length( ) ].add( s ); int idx = 0; for( ArrayList wordList : wordsByLength ) for( String s : wordList ) arr[ idx++ ] = s; int startingIndex = arr.length; for( int pos = maxLen - 1; pos >= 0; pos-- ) { startingIndex -= wordsByLength[ pos + 1 ].size( ); for( int i = startingIndex; i < arr.length; i++ ) buckets[ arr[ i ].charAt( pos ) ].add( arr[ i ] ); idx = startingIndex; for( ArrayList thisBucket : buckets ) { for( String s : thisBucket ) arr[ idx++ ] = s; thisBucket.clear( ); } } } public static void main( String [ ] args ) { List lst = new ArrayList<>( ); Random r = new Random( ); final int LEN = 5; for( int i = 0; i < 100000; i++ ) { String str = ""; int len = LEN; // 3 + r.nextInt( 7 ); // between 3 and 9 characters for( int j = 0; j < len; j++ ) str += (char) ( 'a' + r.nextInt( 26 ) ); lst.add( str ); } String [ ] arr1 = new String[ lst.size( ) ]; String [ ] arr2 = new String[ lst.size( ) ]; lst.toArray( arr1 ); lst.toArray( arr2 ); long start, end; start = System.currentTimeMillis( ); Arrays.sort( arr1 ); end = System.currentTimeMillis( ); System.out.println( "Elapsed: " + ( end - start ) ); start = System.currentTimeMillis( ); countingRadixSort( arr2, LEN ); end = System.currentTimeMillis( ); System.out.println( "Elapsed: " + ( end - start ) ); for( int i = 0; i < arr1.length; i++ ) if( !arr1[ i ].equals( arr2[ i ] ) ) System.out.println( "OOPS!!" ); } }