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LongestPalindrome.java
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LongestPalindrome.java
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package Algorithms.dp;
public class LongestPalindrome {
public static void main(String[] args) {
String s = "9cadfasdfsadfabaabaed";
System.out.println(longestPalindrome(s));
System.out.println(Character.toLowerCase('9'));
}
// Solution 1: Brute Force
public static String longestPalindrome(String s) {
if (s == null) {
return null;
}
int len = s.length();
int max = 0;
int begin = 0;
int end = 0;
for (int i = 0; i < len; i++) {
for (int j = i; j < len; j++) {
if (dfs(s, i, j)) {
if (j - i + 1 > max) {
max = j - i + 1;
begin = i;
end = j;
}
}
}
}
return s.substring(begin, end + 1);
}
public static boolean dfs(String s, int i, int j) {
if (i >= j) {
return true;
}
if (s.charAt(i) == s.charAt(j)) {
return dfs(s, i + 1, j - 1);
}
return false;
}
}