fork(1) download
copy 
  1. using System.Collections.Generic;
  2. using System.Linq;
  3. using static PalindromeChecker;
  4.  
  5. static class PalindromeChecker {
  6.     public static string LongestPalindrome(IEnumerable<string> strings) {
  7.         return strings.Select(LongestPalindromeSubstring).Max();
  8.     }
  9.  
  10.     public static bool IsPalindrome(string s) {
  11.         return s == new string(s.Reverse().ToArray());
  12.     }
  13.  
  14.     public static string AsString(this IEnumerable<char> source) {
  15.         return new string(source.ToArray());
  16.     }
  17.  
  18.     public static string LongestPalindromeSubstring(string s) {
  19.         var end = s.Length;
  20.         var start = 0;
  21.         var longestString = s.Take(1).AsString();
  22.         while ((end-start) > longestString.Length) {
  23.             while ((end - start) > longestString.Length) {//
  24.                 var subs = s.Skip(start).Take(end--).AsString();
  25.                 if (IsPalindrome(subs)) {
  26.                     longestString = subs;
  27.                 }
  28.             }
  29.             start++;
  30.             end = s.Length;
  31.         }
  32.         return longestString;
  33.     }
  34. }
  35.  
  36. public class Test {
  37. 	public static void Main() {
  38. 		var list = new List<string> { "aabbaa","carracecar", "aabbbabab" };
  39. 		System.Console.WriteLine(LongestPalindrome(list));
  40. 	}
  41. }
Success #stdin #stdout 0.02s 131648KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
racecar
https://ideone.com/M4tVmS
language:
C# (gmcs 5.20.1)
created:
8 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!