This is a variation of Abarcadraba.

Consider all possible valid English words having at least 4 letters and at most 13 letters that satisfies the following conditions:

• Each word begins and ends with the same letter, and:
• Reversing the letters we obtain another valid English word, and:
• None of the words can be palindromes, and:
• None of the words can be plurals, proper nouns or abbreviations, and:
• None of the words can be hyphenated like A-bomb, X-ray etc.

What are the respective shortest word and the longest word that satisfy all the given conditions? Does there exist any valid English word having more than 13 letters that satisfies all the conditions?

blub  bulb
bulb  blub
edile  elide
elide  edile
perp  prep
prep  perp
redrawer  rewarder
rewarder  redrawer
sallets  stellas
sleets  steels
snips  spins
snoops  spoons
spans  snaps
spoons  snoops
spots  stops
steels  sleets
stops  spots
stows  swots
struts  sturts
sturts  struts
swots  stows
tort  trot
trot  tort

Word pairs like snips and spins have been left in as they may be singular verbs rather than plural nouns.  I may have been inconsistent as to judging whether a given pair included both words that could be judged as singular verbs as opposed to plural nouns, and so the reverse order might not appear if I judged differently in the two cases.

The longest was redrawer  rewarder, in either order.

The shortest were several, bolded above, that had the minimum length, 4.

None exceeded 13 in length.

Etile doesn't seem to be in my word list.

DECLARE FUNCTION isWord& (wrd$)
OPEN "\words\words.txt" FOR INPUT AS #1
OPEN "elitetil.txt" FOR OUTPUT AS #2
CLS
shortest = 99
DO
 LINE INPUT #1, w$
 IF LEN(w$) >= 3 THEN
   IF LEFT$(w$, 1) = RIGHT$(w$, 1) THEN
     rv$ = ""
     FOR i = 1 TO LEN(w$)
       rv$ = MID$(w$, i, 1) + rv$
     NEXT
     IF rv$ <> w$ THEN
       IF isWord(rv$) THEN
         IF LEN(w$) < shortest THEN shortest = LEN(w$)
         IF LEN(w$) > longest THEN longest = LEN(w$)
         PRINT w$; "  "; rv$
         ct = ct + 1
         IF ct MOD 44 = 0 THEN DO: LOOP UNTIL INKEY$ > "": PRINT
       END IF
     END IF
   END IF
 END IF
LOOP UNTIL EOF(1)
CLOSE
PRINT ct, shortest; longest

DEFLNG A-Z
FUNCTION isWord (wrd$)
  OPEN "\words\words" + LTRIM$(STR$(LEN(wrd$))) + ".txt" FOR BINARY AS #10
  n = LEN(wrd$)
  wrd1$ = SPACE$(n)
  l = LOF(10) / n
  low = 1: high = l
  DO
    mid = INT((low + high) / 2)
    GET #10, (mid - 1) * n + 1, wrd1$
    IF wrd1$ = wrd$ THEN isWord = -1: CLOSE 10: EXIT FUNCTION
    IF wrd1$ < wrd$ THEN low = mid + 1:  ELSE high = mid - 1
  LOOP UNTIL low > high
  isWord = 0
  CLOSE 10
END FUNCTION

 

Posted by Charlie on 2012-01-23 15:21:03