[Swift]判斷連續重複,遞增,遞減的英數字

private func checkHasFourContinuousOrSameWord(str:String)->Int{
        let newPwsd = newCustPswdChg.value
        for i in 0..<newPwsd.count{
            let start = newPwsd.index(newPwsd.startIndex, offsetBy: i)
            var sameStr = ""
            var raisingStr = ""
            var descendingStr = ""
            for k in 0...3{
                let indexNowChar = newPwsd[start]
                //連續重複
                sameStr += newPwsd[start...start]
                //第一位unicode不用加或減
                if k == 0 {
                    raisingStr += String(indexNowChar)
                    descendingStr += String(indexNowChar)
                    continue
                }
                //升冪
                if let firstChar = indexNowChar.unicodeScalars.first {
                    let nextUnicode = firstChar.value + UInt32(k)
                    if let nextChar = UnicodeScalar(nextUnicode) {
                        var nextString = ""
                        nextString.append(Character(UnicodeScalar(nextChar)))
                        print(nextString)
                        raisingStr += nextString
                    }
                }
                //降冪
                if let firstChar = indexNowChar.unicodeScalars.first {
                    let nextUnicode = firstChar.value - UInt32(k)
                    if let nextChar = UnicodeScalar(nextUnicode) {
                        var nextString = ""
                        nextString.append(Character(UnicodeScalar(nextChar)))
                        print(nextString)
                        descendingStr += nextString
                    }
                }
            }
           if newPwsd.contains(sameStr){// 字串包含四位以上的重複字元
                return 1
            }
            if newPwsd.contains(raisingStr) || newPwsd.contains(descendingStr){// 字串包含四位以上的遞增或遞減字元
                return 2
            }
        }
        return -1// 字串不包含四位以上的連續重複、相同、遞增或遞減字元
    }
}