Comments on: How to solve the Multiple Dwellings Puzzle in SQL

By: newkid

newkid — Thu, 24 Jun 2010 20:54:31 +0000

It's not easy to post my code correctly:

WITH comb as (  
       SELECT INSTR(p,'1') AS Baker
             ,INSTR(p,'2') AS Cooper      
             ,INSTR(p,'3') AS Fletcher       
             ,INSTR(p,'4') AS Miller  
             ,INSTR(p,'5') AS Smith     
         FROM ( SELECT REPLACE(SYS_CONNECT_BY_PATH(rn,'\'),'\') AS p
                  FROM (SELECT ROWNUM rn FROM DUAL CONNECT BY ROWNUM <=5)
                 WHERE LEVEL=5
                 CONNECT BY NOCYCLE LEVEL<=5 AND rn != PRIOR rn
                 )
          )
SELECT * FROM comb
WHERE Baker != 5 
      AND Cooper != 1 
      AND Fletcher NOT IN (1,5) 
      AND Miller > Cooper
      AND Smith-Fletcher NOT IN (1,-1)
      AND Cooper-Fletcher NOT IN (1,-1);

     BAKER     COOPER   FLETCHER     MILLER      SMITH
---------- ---------- ---------- ---------- ----------
         3          2          4          5          1

By: newkid

newkid — Thu, 24 Jun 2010 16:48:15 +0000

WITH comb as (
SELECT INSTR(p,’1′) AS Baker
,INSTR(p,’2′) AS Cooper
,INSTR(p,’3′) AS Fletcher
,INSTR(p,’4′) AS Miller
,INSTR(p,’5′) AS Smith
FROM ( SELECT REPLACE(SYS_CONNECT_BY_PATH(rn,’\'),’\') AS p
FROM (SELECT ROWNUM rn FROM DUAL CONNECT BY ROWNUM<=5)
WHERE LEVEL=5
CONNECT BY NOCYCLE LEVEL<=5 AND rnPRIOR rn
)
)
SELECT * FROM comb
WHERE Baker5
AND Cooper1
AND Fletcher NOT IN (1,5)
AND Miller > Cooper
AND Smith-Fletcher NOT IN (1,-1)
AND Cooper-Fletcher NOT IN (1,-1);

BAKER COOPER FLETCHER MILLER SMITH
———- ———- ———- ———- ———-
3 2 4 5 1