Difficulty getting readLine() to work as desired on HackerRank - swift

Question

I'm attempting to submit the HackerRank Day 6 Challenge for 30 Days of Code.
I'm able to complete the task without issue in an Xcode Playground, however HackerRank's site says there is no output from my method. I encountered an issue yesterday due to browser flakiness, but cleaning caches, switching from Safari to Chrome, etc. don't seem to resolve the issue I'm encountering here. I think my problem lies in inputString.
Task
Given a string, S, of length N that is indexed from 0 to N-1, print its even-indexed and odd-indexed characters as 2 space-separated strings on a single line (see the Sample below for more detail).
Input Format
The first line contains an integer, (the number of test cases).
Each line of the subsequent lines contain a String, .
Constraints
1 <= T <= 10
2 <= length of S < 10,000
Output Format
For each String (where 0 <= j <= T-1), print S's even-indexed characters, followed by a space, followed by S's odd-indexed characters.
This is the code I'm submitting:
import Foundation
let inputString = readLine()!
func tweakString(string: String) {
// split string into an array of lines based on char set
var lineArray = string.components(separatedBy: .newlines)
// extract the number of test cases
let testCases = Int(lineArray[0])
// remove the first line containing the number of unit tests
lineArray.remove(at: 0)
/*
Satisfy constraints specified in the task
*/
guard lineArray.count >= 1 && lineArray.count <= 10 && testCases == lineArray.count else { return }
for line in lineArray {
switch line.characters.count {
// to match constraint specified in the task
case 2...10000:
let characterArray = Array(line.characters)
let evenCharacters = characterArray.enumerated().filter({$0.0 % 2 == 0}).map({$0.1})
let oddCharacters = characterArray.enumerated().filter({$0.0 % 2 == 1}).map({$0.1})
print(String(evenCharacters) + " " + String(oddCharacters))
default:
break
}
}
}
tweakString(string: inputString)
I think my issue lies the inputString. I'm taking it "as-is" and formatting it within my method. I've found solutions for Day 6, but I can't seem to find any current ones in Swift.
Thank you for reading. I welcome thoughts on how to get this thing to pass.

Answer 1

readLine() reads a single line from standard input, which
means that your inputString contains only the first line from
the input data. You have to call readLine() in a loop to get
the remaining input data.
So your program could look like this:
func tweakString(string: String) -> String {
// For a single input string, compute the output string according to the challenge rules ...
return result
}
let N = Int(readLine()!)! // Number of test cases
// For each test case:
for _ in 1...N {
let input = readLine()!
let output = tweakString(string: input)
print(output)
}
(The forced unwraps are acceptable here because the format of
the input data is documented in the challenge description.)

Answer 2

Hi Adrian you should call readLine()! every row . Here an example answer for that challenge;
import Foundation
func letsReview(str:String){
var evenCharacters = ""
var oddCharacters = ""
var index = 0
for char in str.characters{
if index % 2 == 0 {
evenCharacters += String(char)
}
else{
oddCharacters += String(char)
}
index += 1
}
print (evenCharacters + " " + oddCharacters)
}
let rowCount = Int(readLine()!)!
for _ in 0..<rowCount {
letsReview(str:String(readLine()!)!)
}