Comments on: How to solve the Anagrams Puzzle in SQL

By: newkid

newkid — Thu, 24 Jun 2010 21:19:38 +0000

SELECT w,wmsys.wm_concat(str),COUNT(*) cnt
  FROM (
SELECT str,REPLACE(SYS_CONNECT_BY_PATH(c,'/'),'/') w
  FROM (
SELECT str
      ,SUBSTR(str,rn,1) c 
      ,ROW_NUMBER() OVER(PARTITION BY str ORDER BY SUBSTR(str,rn,1)) rn
  FROM words, (SELECT ROWNUM rn FROM DUAL CONNECT BY ROWNUM<=(SELECT MAX(LENGTH(str)) FROM words))
 WHERE rn<=LENGTH(str)
 )
WHERE CONNECT_BY_ISLEAF=1
START WITH rn=1
CONNECT BY str=PRIOR str AND rn = PRIOR rn+1
)
GROUP BY w
ORDER BY cnt DESC;

By: newkid

newkid — Thu, 24 Jun 2010 21:06:48 +0000

Well, I might have a misunderstanding of "the same set of letters". How about this?

 
SELECT str 
FROM words,
(SELECT DISTINCT REPLACE(SYS_CONNECT_BY_PATH(c,'/'),'/') w
  FROM (SELECT ROWNUM rn,SUBSTR(:input_str,ROWNUM,1) c FROM DUAL CONNECT BY ROWNUM<=LENGTH(:input_str))
 WHERE LEVEL=LENGTH(:input_str)
CONNECT BY NOCYCLE rn != PRIOR rn  
)
WHERE str=w

By: Frank Zhou

Frank Zhou — Thu, 24 Jun 2010 19:40:26 +0000

Hi newkid,

select TRANSLATE(’angor’,'$’||’organ’,'$’) from dual
VS
select TRANSLATE(’aaaaangor’,'$’||’organ’,'$’) from dual

You will get the same result in both cases, So Transalte function doesn’t work here either.
Also the query’s performance will be slow when using connect by in this case.

Thanks,

Frank

By: newkid

newkid — Thu, 24 Jun 2010 17:10:49 +0000

SELECT * FROM (
SELECT ANAGRAM_CLASS,lvl,RANK() OVER (ORDER BY lvl DESC) RNK
  FROM (
SELECT SYS_CONNECT_BY_PATH(str,'->') ANAGRAM_CLASS,LEVEL lvl
  FROM words 
 CONNECT BY NOCYCLE str>PRIOR str AND TRANSLATE(str,'$'||PRIOR str,'$') IS NULL
 )
 )
WHERE RNK=1;

By: newkid

newkid — Thu, 24 Jun 2010 17:05:46 +0000

SELECT * FROM words WHERE TRANSLATE(str,’$'||:input_str,’$') IS NULL;