Given a string s, return the longest palindromic substring in s.
Example 1:
Input: s = "babad"
Output: "bab"
Explanation: "aba" is also a valid answer.Example 2:
Input: s = "cbbd"
Output: "bb"
Constraints:
1 <= s.length <= 1000
s consist of only digits and English letters.
class Solution {
public:
int check(string &s, int L, int R)
{
while(L>=0 and R<s.length() and s[L]==s[R])
{
L--;
R++;
}
return R-L-1;
}
string longestPalindrome(string s) {
int ans = 0, st=0;
int n = s.length();
for(int i = 0;i<n;i++)
{
int len1 = check(s, i,i);
int len2 = check(s, i, i+1);
int len = max(len1, len2);
if(len> ans)
{
ans = len;
st = i-(len-1)/2;
}
}
return s.substr(st, ans);
}
};
