整数数组中连续递增子序列转化问题

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

//有一组数据 例如[1，3，8，17，18，19，20，50，60，72，73，74],
//[1,3,8,17~20,50,60,72~74]这种形式
public class Test
{
    public static List<String> convert(int ...src)
    {
        int pre,loc,next;
        String strtmp="~";
        List<Integer> desc=new ArrayList<Integer>();
        List<String> res=new ArrayList<String>();
        for(int s:src)
        {
            desc.add(s);
        }
        Iterator<Integer> itr=desc.iterator();
        pre=itr.next();
        loc=itr.next();
        while(itr.hasNext())
        {
            next=itr.next();
            if(pre+1!=loc&&loc+1==next)
            {
                strtmp=pre+"\n"+loc;
                res.add(strtmp);
            }
            else if(pre+1==loc&&loc+1==next&&!strtmp.equals("~"))
            {
                strtmp="~";
                res.add(strtmp);
            }
            else if(pre+1!=loc&&loc+1!=next)
            {
                strtmp=String.valueOf(pre);
                res.add(strtmp);
            }
            pre=loc;
            loc=next;
        }
        res.add(String.valueOf(loc));
        return res;
    }
    public static void main(String[] args)
    {
        int[] src={1,3,8,17,18,19,20,50,60,72,73,74};
        List<String> lis=convert(src);
        List<String> res=new ArrayList<String>();
        String[] arr=new String[lis.size()];
        for(int i=0;i<lis.size();i++)
        {
            arr[i]=lis.get(i);
        }
        for(int i=0;i<arr.length-2;i++)
        {
            if(arr[i+1].equals("~"))
            {
                res.add(arr[i]+"~"+arr[i+2]);
                i+=2;
            }
            else
            {
                res.add(arr[i]);
            }
        }
        Iterator<String> itr=res.iterator();
        while(itr.hasNext())
        {
            System.out.print(itr.next()+"\t");
        }
    }
}