Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.
Example 1:
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Input: "babad"
Output: "bab"
Note: "aba" is also a valid answer.
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Example 2:
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Input: "cbbd"
Output: "bb"
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给定字符串s，最长的回文子串。假设s的长度小于等于1000.
分析：又是一个笨办法，双重遍历得到子串，得到子串后进行两个判断，首先判断是否比之前确定是回文串的子串长，如果是判断是否是回文串，如果不是，则不需要继续判断了。详细代码如下：
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class {
public String longestPalindrome(String s) {
if (s == null || s.isEmpty()) {
return "";
}
final int slen = s.length();
int longest = 0, left = 0;
for (int i = 0; i < slen; i++) {
for (int j = i; j < slen; j++) {
if (j - i + 1 > longest && isPalindrome(s, i, j)) {
longest = j - i + 1;
left = i;
}
}
}
return s.substring(left,left + longest);
}
private static boolean isPalindrome(String s, int left, int right) {
for (int i = left, j = right; i <= j; i++, j--) {
if (s.charAt(i) != s.charAt(j)) {
return false;
}
}
return true;
}
}
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