title: Longest Prefix Also Suffix 1
signature: class Solution {
  
      public int LongestPrefixAlsoSuffix1(string s) {
test_code: using System;
  using System.Numerics;
  using System.Diagnostics;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Security.Cryptography;
  using System.Web.UI;
  using System.Web.Script.Serialization;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  namespace EvaluatePrediction {
      class TestRunner {
          public bool ValidateSolution(int actual, int expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(string s, int expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                int pred_result = solution_cls.PLACEHOLDER_FN_NAME(s); 
                if (ValidateSolution(
                      pred_result,
                      expected)){
                  return "PASSED";
                }
                return "FAILED";
              } 
              catch (Exception exception_obj)
              {
                return exception_obj.GetType().FullName;
              }
          }
          static void Main(string[] args) {
              TestRunner runner = new TestRunner();
              String result;
              result = runner.driver(
                  "aabcdaabc", 
                  4
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  "1372494598", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  "110000100001", 
                  1
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  "abcab", 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  "488938", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  "011010101011", 
                  3
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  "aaaa", 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  "3356203205", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  "1010", 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  "kkXiiTZkGeh", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def longest_prefix_also_suffix_1(s):
      n = len(s)
      lps = ([0] * n)
      l = 0
      i = 1
      while (i < n):
          if (s[i] == s[l]):
              l = (l + 1)
              lps[i] = l
              i = (i + 1)
          elif (l != 0):
              l = lps[(l - 1)]
          else:
              lps[i] = 0
              i = (i + 1)
      res = lps[(n - 1)]
      if (res > (n / 2)):
          return (n // 2)
      else:
          return res
source_cpp: int longest_prefix_also_suffix_1(string s) {
    int n = s . length ( );
    int lps [ n ];
    lps [ 0 ] = 0;
    int len = 0;
    int i = 1;
    while ( i < n ) {
      if ( s [ i ] == s [ len ] ) {
        len ++;
        lps [ i ] = len;
        i ++;
      }
      else {
        if ( len != 0 ) {
          len = lps [ len - 1 ];
        }
        else {
          lps [ i ] = 0;
          i ++;
        }
      }
    }
    int res = lps [ n - 1 ];
    return ( res > n / 2 ) ? n / 2 : res;
  }