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  1. //package pkg1297palindrome;
  2.  
  3. import java.io.*;
  4. import java.util.*;
  5.  
  6. public class Main {
  7.  
  8.     InputReader in;
  9.     PrintWriter out;
  10.  
  11.     public static void main(String[] args) {
  12.         new Main().Run();
  13.     }
  14.  
  15.     void Solve() throws Exception{
  16.         String s;
  17.         s = in.readLine();
  18.         int n = s.length();
  19.         char[] ss = s.toCharArray();
  20.         s = "";
  21.         for(int i = 0; i < n; i++) s = s + ss[i] + "0";
  22.         int m = s.length();
  23.         char[] s2 = s.toCharArray();
  24.         int max = 1, M = 1;
  25.         for(int i = 1; i < m - 1; i++){
  26.             int L = i, R = i;
  27.             while(s2[L] == s2[R]){
  28.                 L--; R++;
  29.                 if(L < 0 || R >= m) {
  30.                     L++; R--; break;
  31.                 }
  32.             }
  33.             if(max < R - L + 1){
  34.                 max = R - L + 1;
  35.                 M = i;
  36.             }
  37.         }
  38.         s = "";
  39.         int L = M, R = M;
  40.         while(s2[L] == s2[R]){
  41.             if(s2[L] != '0') {
  42.                 if(L != R) s = s2[L] + s + s2[R];
  43.                 else s = s + s2[L];
  44.             }
  45.             L--; R++;
  46.             if(L < 0 || R >= m) break;
  47.         }
  48.         out.println(s);
  49.     }
  50.  
  51.     public void Run(){
  52.         try{
  53.             File defaultInput = new File("text.inp");
  54.             if(defaultInput.exists()) in = new InputReader("text.inp");
  55.             else in = new InputReader();
  56.             out = new PrintWriter(System.out);
  57.             Solve();
  58.             out.close();
  59.         } catch (Exception e){
  60.             e.printStackTrace();
  61.             System.exit(261);
  62.         }
  63.     }
  64.  
  65.     class InputReader {
  66.         BufferedReader reader;
  67. 	StringTokenizer tokenizer;
  68.  
  69. 	InputReader() {
  70.             reader = new BufferedReader(new InputStreamReader(System.in));
  71.         }
  72.  
  73. 	InputReader(String fileName) throws FileNotFoundException {
  74.             reader = new BufferedReader(new FileReader(new File(fileName)));
  75. 	}
  76.  
  77. 	String readLine() throws IOException {
  78.             return reader.readLine();
  79. 	}
  80.  
  81.         String nextToken() throws IOException {
  82.             while (tokenizer == null || !tokenizer.hasMoreTokens())
  83.             tokenizer = new StringTokenizer(readLine());
  84.             return tokenizer.nextToken();
  85. 	}
  86.  
  87. 	boolean hasMoreTokens() throws IOException {
  88.             while (tokenizer == null || !tokenizer.hasMoreTokens()) {
  89.                 String s = readLine();
  90.                 if (s == null) return false;
  91. 		tokenizer = new StringTokenizer(s);
  92.             }
  93.             return true;
  94. 	}
  95.  
  96. 	int nextInt() throws NumberFormatException, IOException {
  97.             return Integer.parseInt(nextToken());
  98. 	}
  99.  
  100. 	long nextLong() throws NumberFormatException, IOException {
  101.             return Long.parseLong(nextToken());
  102. 	}
  103.  
  104.         double nextDouble() throws NumberFormatException, IOException {
  105.             return Double.parseDouble(nextToken());
  106. 	}
  107.     }
  108.  
  109. }
  110.  
Runtime error #stdin #stdout #stderr 0.07s 381184KB
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stdin
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Standard input is empty
stdout
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Standard output is empty
stderr
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java.lang.NullPointerException
	at Main.Solve(Main.java:18)
	at Main.Run(Main.java:57)
	at Main.main(Main.java:12)
https://ideone.com/cfqTA0
language:
Java (HotSpot 12)
created:
11 years ago
visibility:
public

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