/* * * @ Javier Felipe Toribio 2021-01-09 * * challenge by Tarvs * * Search all substrings into a string that * are palindromes * * Write a program that takes in a string as * input and outputs all the palindromes that can * be found in that string. * Sample input - "abba" * Output - "abba" and "bb" * That's because "abba" and "bb" are the only * palindromes in "abba" * * Sample input - "102ab5baba" * Output - "ab5ba" and "aba" and "bab" * * Bonus points=> only print out distinct * palindromes. * So if input = "aabaa" * Output = "aabaa" and "aa" * Instead of "aabaa" and "aa" and "aa" * */ import java.util.*; public class Program { public static List search_palindromes (String str, int start, int end) { List results = new ArrayList<>(); int prev = start; int next = end; while(prev >= 0 && next <= str.length()-1) { if(str.charAt(prev) != str.charAt(next)) return results; results.add(str.substring(prev, next+1)); --prev; ++next; } return results; } public static Set search(String str) { List palindromes = new ArrayList<>(); List results; if(str.length() < 3) return new HashSet(); for(int i = 0 ; i < str.length()-1; i++) { results = search_palindromes(str,i-1,i+1); palindromes.addAll(results); results = search_palindromes(str,i,i+1); palindromes.addAll(results); } return new HashSet(palindromes); } public static void solve(String str) { System.out.println("Original string : " + str); System.out.println("\nPalindromes :\n"); for(String palindrome : search(str)) System.out.println(palindrome); System.out.println("\n"); } public static void test_case_1() { solve("abba"); } public static void test_case_2() { solve("102ab5baba"); } public static void test_case_3() { solve("aabaa"); } public static void main(String[] args) { test_case_1(); test_case_2(); test_case_3(); } }

[challenge] palindromes in string