Merge pull request #350 from zafar-hussain/anagramBranch

Adding Check two strings are anagrams - in Racket - for issue #53

Author: Kanhakhatri065

problems/Anagram/isAnagram?.rkt

@@ -0,0 +1,32 @@
+#lang racket
+;Check weather the given two strings are anagrams of each other, i.e weather they contain the same letter.
+;
+;Example :
+;Input: abc & cab //abc is anagrams with cab, bac, cab..
+;Output: True
+
+;; string -> boolean
+;; retruns true of given strings have the same characters
+
+;; code
+;(define (isAnagram? s1 s2) true)  ; stub
+
+(define (isAnagram? s1 s2)
+  (local [(define (isAnagram? s1 s2)                                                                    ; helper function
+            (cond
+              [(and (empty? s1) (empty? s2)) true]                                                      ; basecase for recursion
+              [else
+               (and                                                                                     ; all the characters must match
+                (equal? (first s1) (first s2))
+                (isAnagram? (rest s1) (rest s2)))]))]
+    (isAnagram? (sort (string->list s1) (lambda (a b) (> (char->integer a) (char->integer b))))         ; turning the string into a 
+                (sort (string->list s2) (lambda (a b) (> (char->integer a) (char->integer b)))))))      ; sorted list
+
+
+
+
+
+;; testing examples
+;(equal? (isAnagram? "" "") true)    ; basecase
+;(equal? (isAnagram? "abc" "cab") true)
+;(equal? (isAnagram? "cat" "dog") false)