Difference between revisions of "99 questions/Solutions/6"
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isPalindrome :: (Eq a) => [a] -> Bool |
isPalindrome :: (Eq a) => [a] -> Bool |
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isPalindrome xs = xs == (reverse xs) |
isPalindrome xs = xs == (reverse xs) |
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| + | </haskell> |
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| + | |||
| + | <haskell> |
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| + | isPalindrome' [] = True |
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| + | isPalindrome' [x] = True |
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| + | isPalindrome' xs = (head xs) == (last xs) && (isPalindrome' $ init $ tail xs) |
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</haskell> |
</haskell> |
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Revision as of 07:28, 17 November 2010
(*) Find out whether a list is a palindrome. A palindrome can be read forward or backward; e.g. (x a m a x).
isPalindrome :: (Eq a) => [a] -> Bool
isPalindrome xs = xs == (reverse xs)
isPalindrome' [] = True
isPalindrome' [x] = True
isPalindrome' xs = (head xs) == (last xs) && (isPalindrome' $ init $ tail xs)