Poj Solution 2887

http://poj.org/problem?id=2887

//* @author: 82638882@163.com
import java.io.*;
public class Main
{
 public static void main(String[] args) throws IOException
 {
   InputStreamReader is=new InputStreamReader(System.in);
   BufferedReader in=new BufferedReader(is);
   int[] s=new int[1000010];
   int size=0;
   while(true)
   {
    int u=in.read();
    if(u=='n')break;
    s[size++]=u;
    }
   int n=Integer.parseInt(in.readLine());
   int[] arr=new int[n];
   char[] crr=new char[n];
   int l=0;
   for(int i=0;i< n;i++)
   {
    int ww=in.read();
    if(ww=='Q')
    {
        in.read();
     int u=0;
     while(true)
     {
      int temp=in.read();
      if(temp>='0'&&temp<='9')
      {
        u*=10;
        u+=temp-'0';
      }
      else break;
     }
     char ans='';
     for(int j=l-1;j>=0;j--)
     {
      if(arr[j]< u) u--;
      else if(arr[j]==u){
        ans=crr[j];
        break;
      }
     }
    if(ans=='')
        ans=(char)s[u-1];
    System.out.println(ans);
     }
    else if(ww=='I')
    {
    in.read();
    crr[l]=(char)in.read();
    in.read();
    int u=0;
    while(true)
    {
       int temp=in.read();
       if(temp>='0'&&temp<='9')
       {
        u*=10;
        u+=temp-'0';
       }
       else break;
     }
    if(u>l+size) u=l+size+1;
    arr[l]=u;
    l++;
     }
     in.readLine();
   }
 }
}