hdu--4148--Length of S(n)

#include<iostream>
#include<string>
#include<cstring>
void priTable();
using namespace std;
int arr[30];
int main()
{
    int n;
    priTable();
    while(cin>>n && n!=0){
        cout<<arr[n-1]<<endl;
    }
    return 0;
}
void priTable(){
    arr[0]=1;
    string s="1";
    int count=1;
    string next="";
    for(int i=1;i<=29;++i)
    {
        for(int j=0;j<s.length();){
            char temp=s[j];
            int num=0;
            while(s[j]==temp){
                j++;num++;
            }
            next+='0'+num;
            next+=temp;
        }
        arr[i]=next.length();
        s=next;
        next="";
    }
}