PAT 1031

简单题，字符串处理，注意index就可以了

 1 import java.util.*;
 2 import java.io.*;
 3
 4 class FastReader{
 5     BufferedReader reader;
 6     StringTokenizer tokenizer;
 7
 8     public FastReader(InputStream stream){
 9         reader = new BufferedReader(new InputStreamReader(stream), 1 << 10);
10         tokenizer = null;
11     }
12
13     public String next(){
14         while (tokenizer == null || !tokenizer.hasMoreTokens()){
15             try{
16                 tokenizer = new StringTokenizer(reader.readLine());
17             } catch (Exception e){
18                 throw new RuntimeException(e);
19             }
20         }
21
22         return tokenizer.nextToken();
23     }
24
25     public long next_long(){
26         return Long.parseLong(next());
27     }
28
29     public int next_int(){
30         return Integer.parseInt(next());
31     }
32 }
33
34 public class Main {
35     public static void main(String[] args){
36         FastReader reader = new FastReader(System.in);
37         String process_str = reader.next();
38
39         int size = process_str.length() + 2;
40         int n1, n2, n3;
41
42         n1 = n3 = size / 3;
43         n2 = n1 + size % 3;
44         size -= 2;
45
46         StringBuilder white_space = new StringBuilder();
47         for (int i = 0; i < n2 - 2; i++)
48             white_space.append(‘ ‘);
49
50         for (int i = 0; i < n1 - 1; i++)
51             System.out.println(process_str.charAt(i) + white_space.toString() + process_str.charAt(size - i - 1));
52         for (int i = n1 - 1; i <= size - n1; i++)
53             System.out.print(process_str.charAt(i));
54         System.out.println();
55     }
56 }