{"id":23,"date":"2007-07-26T23:20:29","date_gmt":"2007-07-27T06:20:29","guid":{"rendered":"http:\/\/www.elbeno.com\/haskell_soe_blog\/?p=23"},"modified":"2008-01-07T22:05:38","modified_gmt":"2008-01-08T06:05:38","slug":"exercise-59","status":"publish","type":"post","link":"https:\/\/www.elbeno.com\/haskell_soe_blog\/?p=23","title":{"rendered":"Exercise 5.9"},"content":{"rendered":"<pre lang=\"haskell\">makeChange :: Int -> [Int] -> [Int]\r\nmakeChange _ [] = []\r\nmakeChange 0 _ = []\r\nmakeChange amt (v:vs) = n : (makeChange newamt vs)\r\n    where n = amt `div` v\r\n          newamt = amt `mod` v<\/pre>\n<p>This was one tricky to do with higher-order functions, until I discovered <tt>scanl<\/tt>.<\/p>\n<pre lang=\"haskell\">makeChange' :: Int -> [Int] -> [Int]\r\nmakeChange' amt vs = zipWith div modvs vs\r\n    where modvs = scanl mod amt vs<\/pre>\n<p>See <a href=\"http:\/\/haskell.org\/soe\/Bug\/erata.htm\">technical error 12<\/a> for a note about this exercise.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>makeChange :: Int -> [Int] -> [Int] makeChange _ [] = [] makeChange 0 _ = [] makeChange amt (v:vs) = n : (makeChange newamt vs) where n = amt `div` v newamt = amt `mod` v This was one tricky to do with higher-order functions, until I discovered scanl. makeChange&#8217; :: Int -> [Int] [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/23"}],"collection":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=23"}],"version-history":[{"count":0,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/23\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}