LeetCode 2. Add Two Numbers swift

//
//  main.swift
//  leetcode02
//
//  Created by GuoLa on 16/1/21.
//  Copyright © 2016年 GuoLa. All rights reserved.
//

import Foundation

func input() -> String {
    let keyboard = NSFileHandle.fileHandleWithStandardInput()
    let inputData = keyboard.availableData
    let strData = NSString(data: inputData, encoding: NSUTF8StringEncoding)!
    return strData.stringByTrimmingCharactersInSet(NSCharacterSet.newlineCharacterSet())
}

class ListNode{
    var val:Int
    var next:ListNode?
    init(_ num: Int)
    {
        val=num
        next=nil
    }

    func desc()->String{

        var ret:String = String(val)
        var node = next
        while node != nil {
            ret = ret.stringByAppendingFormat("->%d", (node?.val)!)
            node=node!.next
        }
        return ret
    }
}

public class SolutionAddTwoNumbers{
    func addTwoNumbers(l1: ListNode?,l2: ListNode?) ->ListNode{
        let ret:ListNode = ListNode(-1)
        var p1=l1
        var p2=l2
        var p:ListNode = ret

        if l1 == nil { ret.next = l2; return ret;}
        if l2 == nil { ret.next = l1; return ret;}

        var p1count = 0
        while p1 != nil {
            p1=p1?.next
            p1count++
        }
        var p2count = 0
        while p2 != nil {
            p2=p2?.next
            p2count++
        }

        if p2count > p1count {
            p1=l2
            p2=l1
        }else
        {
            p1=l1
            p2=l2
        }

        while p1 != nil {

            if p2 == nil {
                var sum=p1!.val
                if p.next != nil {
                    sum+=(p.next!.val);
                }
                p.next=ListNode(sum%10)
                p=p.next!

                if sum/10 > 0 { p.next = ListNode(1) }
                p1=p1?.next

            }
            while p2 != nil {
                var sum=p1!.val+p2!.val
                if p.next != nil {
                    sum+=(p.next!.val);
                }

                p.next=ListNode(sum%10)
                p=p.next!

                if sum/10 > 0 { p.next = ListNode(1) }

                p1=p1!.next
                p2=p2!.next

               }
        }

        return ret.next!;
    }
}

func ListNodeCreate(str: String) ->ListNode {
    let str:[String] = str.componentsSeparatedByString("->")
    var list:ListNode = ListNode(-1)
    let ret = list

    for s in  str {
        list.next = ListNode(Int(s)!)
        list=list.next!
    }

    return ret.next!
}

var testCaseAddTowNumber = SolutionAddTwoNumbers()

var l1:String = ""
repeat{

print("Enter ListNode1:(Input exit,Program end!)")

//var l1 = "2->3->4"
l1 = input()
if l1 == "exit" {break}

print("Enter ListNode2:")
//var l2 = "1->2->3"
var l2 = input()

let nodel1 = ListNodeCreate(l1)
let nodel2 = ListNodeCreate(l2)

print(nodel1.desc())
print(nodel2.desc())

var tow = SolutionAddTwoNumbers()
var ret = tow.addTwoNumbers(nodel1, l2: nodel2)

print(ret.desc())
} while l1 != "exit"

测试输入

1->8

0

结果：1->8

0

7->3

结果 7->3

3
4->2
结果：7 2

6
4->2
结果：0 3

3->4->5
1->2->3
结果：4->6->8

9->4->5
1->2->3
结果：0->7->8

3->8->5
1->2->3
结果：4->0->9

3->4->7
1->2->3
结果：4->6->0->1