{"id":61,"date":"2010-03-01T22:15:35","date_gmt":"2010-03-01T21:15:35","guid":{"rendered":"http:\/\/www.aymericlamboley.fr\/blog\/?p=61"},"modified":"2010-05-10T13:39:45","modified_gmt":"2010-05-10T12:39:45","slug":"recursion-with-factorial","status":"publish","type":"post","link":"http:\/\/www.aymericlamboley.fr\/blog\/recursion-with-factorial\/","title":{"rendered":"Recursion with factorial"},"content":{"rendered":"

A recursive function is a procedure or subroutine, implemented in a programming language, whose implementation references itself.
\nIt is really useful, try to make a program like Tower of Hanoi<\/a> with an iterative algorithm… good luck !<\/p>\n

So I will give you an easy method to create a recursive algorithm, I choose the example of factorial<\/a> because of it simplicity.
\nMathematical’s reminder : 4! = 4 * 3 * 2 * 1 = 24.<\/p>\n

There are 3 steps :
\n– parameter(s) : identify all the parameters that you need to resolve the problem. They will decrease at each call of the function. In the factorial’s case, it is the factorial’s number.<\/p>\n

function factorialCalculation(factorial:uint):uint<\/pre>\n
– exception’s case : this is when the procedure stops to call itself.<\/p>\n
if (factorial == 1) { return 1; }<\/pre>\n
– recursive’s case : where recursive call is implemented, don’t forget to decrease (generally) parameter(s).<\/p>\n
return factorial * factorialCalculation(factorial - 1);<\/pre>\n
Now all the code :<\/p>\n
var factorial:uint = 4;\r\nvar resul:uint = 0;\r\n\r\nresul = factorialCalculation(factorial);\r\n\r\nfunction factorialCalculation(factorial:uint):uint {\r\n\r\n\tif (factorial == 1) {\r\n\t\treturn 1;\r\n\t} else {\r\n\t\treturn factorial*factorialCalculation(factorial-1);\r\n\t}\r\n}<\/pre>\n
Be careful : recursive function are really heavy. Factorial’s case is just an easy example, it should be implemented as an interative function !
\n<\/strong>
\nAnd for the fun with a ternary operation<\/a> :<\/p>\n
function factorialCalculation(factorial:uint):uint {\r\n\r\n\treturn (factorial == 1) ? 1 : factorial * factorialCalculation(factorial - 1);\r\n}<\/pre>\n
\ud83d\ude00<\/p>\n","protected":false},"excerpt":{"rendered":"
A recursive function is a procedure or subroutine, implemented in a programming language, whose implementation references itself. It is really useful, try to make a program like Tower of Hanoi with an iterative algorithm… good luck ! So I will give you an easy method to create a recursive algorithm, I choose the example of … Continue reading Recursion with factorial<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[6],"tags":[],"_links":{"self":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts\/61"}],"collection":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/comments?post=61"}],"version-history":[{"count":11,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts\/61\/revisions"}],"predecessor-version":[{"id":951,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts\/61\/revisions\/951"}],"wp:attachment":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/media?parent=61"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/categories?post=61"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/tags?post=61"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}