题解 | #进制转换#

import Foundation

while let line = readLine() {
   var lineArray = Array(line)
   var res = 0
   for i in 2..<lineArray.count {
        res = res * 16
       let ch = lineArray[i]
       if ch.isNumber {
        res += Int(String(ch))!
       } else {
         res += Int(ch.asciiValue!) - 65 + 10
       }
   }
    print(res)
}