ドア

10951

10951
letでなければ.
while letの使用

import Foundation
while let intArr = readLine()?.components(separatedBy: " ").map( {Int($0)!} ) {
    print(intArr[0] + intArr[1])
}

10952

10952
配列[0,0]を表す

import Foundation

while true {
    let intArr = readLine()!.components(separatedBy: " ").map( {Int($0)!} )
    if intArr == [0, 0] {
        break
    }
    print(intArr[0] + intArr[1])
}

1110

1110
繰り返し使用
newnumberの先変後値が等しいかどうかを比較できます.

import Foundation

let input = Int(readLine()!)!

var newNumber: Int = 0
var count: Int = 0

newNumber = input

repeat {
    let tens = newNumber / 10
    let units = newNumber % 10
    let sum = tens + units
    
    newNumber = units*10 + sum%10
    count += 1
} while (input != newNumber)

print(count)