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Editorial Team
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Asked: 2026-06-13T01:20:50+00:00

I’m trying to solve the square anagram word pair problem of project Euler (

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I’m trying to solve the “square anagram word pair” problem of project Euler (here) in Haskell, but I’m stucked…

The problem is the following (I shortened it):

  • take one word, say “CARE” and one of its anagram, for example “RACE”.
  • replace each letter of “CARE” by a unique digit, for example C = 1, A = 2, R = 9 and E = 6. It happens to be 1296 and is a square number.
  • replace the anagram’s letters (“RACE”) following the same substitution policy, it generates 9216 which also is a square number !

Given a list of words, what’s the largest square number formed by any
member of such a pair?

I managed to extract all the anagrams pairs from the file and I have them in a [(String,String)] form i.e [(“CARE”,”RACE”)..].

In the next step (map anasquare), and for each pair of words, I want to link the biggest square number that can be generated so it’d look like[(9216,”CARE”,”RACE”)..].

Well, there is a trick (there must be !) to avoid the brute force approach but so far I didn’t find it… Actually the problem isn’t here, let’s say I want to take the brute force approach and check every letter -> digit transformations. I just don’t know how to do it in Haskell. Maybe I’m tired but I’m just dumbstruck in front of this. There must be a short an elegant yet not too obscure way to write it, someone has an idea ?

Here’s what I do, I spare you the anagram searching and the file parsing functions:

-- Read the file -> store the content into a list -> work on that list -> print the output
result98 = do contents <- readFile ".\\resources\\98.txt"
              putStrLn $ (process.words.format) contents

-- Find anagram pairs -> Find corresponding square number -> get the biggest one
process::[String]->String
process = toString . maximum . map anasquare . anagrams
    where toString (a,b,c) = "Yay ! the result is " ++ show a

-- Generate the maximum square number possible, 0 when none exist
anasquare::(String,String)->(Integer,String,String)
anasquare (x,y) = (anasquareValue,x,y)
    where anasquareValue = 0 -- TODO
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1 Answer

  1. Editorial Team

    Though the mathematical insight is useful (especially on project euler), it didn’t help me much on that one since I was missing some knowledge on the ‘how to’ part.

    Without going too much into the details, one solution path would consist in transforming an anagram word ("CARE","RACE") into a pair such as (1234,4213). Straightforward stuff. If a similar pattern is detected in the square number pairs, then there’s a match.

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