The beauty of Haskell

Ah, the beauty of Haskell, solving the graceful labeling node generation (brute force mind you, but still...)

vonKoch edges = do
    let n = length edges + 1
    nodes <- permutations [1..n]
    let nodeArray = listArray (1,n) nodes
    let dists = sort $ map (\(x,y) -> abs (nodeArray ! x - nodeArray ! y)) edges
    guard $ and $ zipWith (/=) dists (tail dists)
    return nodes




(solution found here: http://www.haskell.org/haskellwiki/99_questions/Solutions/92)







































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