7. 反转整数 LeetCode

image.png

class Solution {
    func reverse(_ x: Int) -> Int {
       var str = "\(x)";
        var char = "";
        if x < 0{
            char = String(str.prefix(1));
            str = String(str.suffix(str.count - 1))
        }
        var arr:[String] = []
        for i in str{
            arr.insert(String(i), at: 0)
        }
        str = arr.joined(separator: "")
        str = char + str
        if let result = Int32(str){
            return Int(result)
        }else{
            return 0;
        }
    }
}