3_b_5: Add solution

1 files changed, 22 insertions, 0 deletions

diff --git a/ch03/3_b_5.hs b/ch03/3_b_5.hs
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+-- Write a function that determines whether its input list is a palindrome.
+
+reverseList [] = []
+reverseList (x:xs) = (reverseList xs) ++ [x]
+
+isPalindrome xs = xs == (reverseList xs)
+
+-- ghci> :l 3_b_5.hs
+-- [1 of 1] Compiling Main             ( 3_b_5.hs, interpreted )
+-- Ok, one module loaded.
+-- ghci> isPalindrome []
+-- True
+-- ghci> isPalindrome [1]
+-- True
+-- ghci> isPalindrome [1, 2]
+-- False
+-- ghci> isPalindrome [1, 2, 1]
+-- True
+-- ghci> isPalindrome [1, 2, 2, 1]
+-- True
+-- ghci> isPalindrome [1, 2, 3, 2, 4]
+-- False