Valid Anagram

[kevin]

Valid Anagrams

How do you detect if two strings are anagrams or not in PlayBASIC ?    This is one of those coding questions that popped up in my socials recently.  On the surface all we need do is check if the two strings contain the same letters, if they do, they're anagrams.

Assuming the strings only contain alphabetically characters in lower case (a,b,c etc etc x,y,z) , we can use an array to count the number of times each character occurs.  So we could do this two both strings and them compared the counts, if no differences are found the two strings are indeed anagrams.    But that requires two tables

However you can just use one integer array and simply add and subtract one for each occurrence of each character within the array.  Which is how the following solution works. 

Code Select Expand

242. Valid Anagram

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

 

Example 1:

Input: s = "anagram", t = "nagaram"
Output: true

Example 2:

Input: s = "rat", t = "car"
Output: false
 

Constraints:

    1 <= s.length, t.length <= 5 * 104
    s and t consist of lowercase English letters.


PlayBASIC Code: [Select]

    print IsAnagram("anagram"    , "nagaram")
    print IsAnagram("rat"        ,  "car")
    
    sync
    waitkey
    


function IsAnagram(A$, B$)
    // dumpg to debug
    #print "IsAnagram("+A$+","+B$+")"

    // Are these even the same size ?? , if not exit        
    local A_size =len(A$)
    local B_size =len(B$)
    if A_Size<>B_Size then exitfunction false

    Dim CharacterMAP(asc("z"))
    for lp =1 to A_Size
        CharacterMAP(mid(a$,lp)-asc("a"))++
        CharacterMAP(mid(b$,lp)-asc("a"))--
    next

    for lp =0 to asc("z")- asc("a")
        if CharacterMap(lp)<>0        
            exitfunction false            
        endif
    next

endfunction true