Leetcode Longest Palindromic Substring problem solution in C++

class Solution {
public:
    string longestPalindrome(string s) {
     int n=s.length();
    
     if(s.length()==0){
         return "";
     }
    
    string ans;
    int max_len=0;
    
        for(int i=0;i<n;i++){
   //here we check at every index if we can found the palindrome with middle index as i
  //now two cases arrives palindrome with even length
 //palindrome with odd length          
             int j=0 ;
             while(i-j>=0&&i+j<n&&s[i-j]==s[i+j])
             {//this loop will handle palindrome with odd length
                  
                    if(max_len<2*j+1)
                    {
                        max_len=2*j+1;
                        ans=s.substr(i-j,2*j+1);
                      
                    }  
                     j++;
             }
            j=1;
            while(i-j+1>=0&&i+j<n&&s[i-j+1]==s[i+j])
            {//this loop will handle palindrome with even length
                   int curr_len=2*j;
                if(max_len<curr_len)
                {
                    max_len=curr_len;
                    ans=s.substr(i-j+1,2*j);
                }
                j++;
            }
        }
    return ans;
}
};