Problem · String
Recursive Character Frequency
Learn this problemProblem statement
Count character frequencies in text by traversing the string recursively, without an explicit loop. Fold ASCII letters A through Z to lowercase before counting; leave other printable ASCII characters unchanged.
Return one entry per distinct folded character in ascending ASCII order. Encode a space as space=count and every other character as character=count.
Function
recursiveCharacterFrequency(text: String) → String[]Examples
Example 1
text = "This is PANW Interview"return = ["space=3","a=1","e=2","h=1","i=4","n=2","p=1","r=1","s=2","t=2","v=1","w=2"]Uppercase letters fold to lowercase, three spaces are counted, and the entries follow ASCII order.
Example 2
text = "Aa!!"return = ["!=2","a=2"]A and a share one folded count, while the exclamation mark remains unchanged.
Constraints
0 <= text.length <= 500.- Every character has an ASCII code from
32through126. - The submitted traversal must be recursive and must not use explicit looping statements.