#ifndef S0005_LONGEST_PALINDROMIC_SUBSTRING_HPP
#define S0005_LONGEST_PALINDROMIC_SUBSTRING_HPP

#include <algorithm>
#include <string>
#include <vector>

using namespace std;

typedef struct S0005ResultStruct {
  int left1;  // 边界情况为长度为 1 的字符时，扩展完成后的左边界
  int right1;  // 边界情况为长度为 1 的字符时，扩展完成后的右边界
  int left2;  // 边界情况为长度为 2 的字符串时，扩展完成后的左边界
  int right2;  // 边界情况为长度为 2 的字符串时，扩展完成后的右边界
} S0005Result;

class S0005 {
 public:
  /**
   * @brief Longest Palindromic Substring
   *
   * Given a string s, return the longest palindromic substring in s.
   *
   * @param s the given string
   * @return longest palindromic substring
   */
  string longestPalindrome1(string s);
  /**
   * @brief Longest Palindromic Substring
   *
   * Given a string s, return the longest palindromic substring in s.
   *
   * @param s the given string
   * @return longest palindromic substring
   */
  string longestPalindrome2(string s);
  S0005Result expand(string s, int i);
};

#endif