Longest_Palindromic_Substring_Problem.cpp

#Longest_Palindromic_Substring_Problem

class Solution {
public:
    string longestPalindrome(string s) {
        int n=s.size();
        if(n==0)return "";
        int i=0;
        int maxi=0;
        string ans="";
        int lef,rig;
        while(i<n){
            //odd case
                 lef=i; rig=i;
                while(lef>=0&&rig<=n-1&&s[lef]==s[rig]){
                     if(maxi<rig-lef+1){
                    string t(s.begin()+lef,s.begin()+rig+1);
                    ans=t;
                    maxi=rig-lef+1;
                }
                    lef--;
                    rig++;
                }
               
                
            
          //even case
                 lef=i;rig=i+1;
                while(lef>=0&&rig<=n-1&&s[lef]==s[rig]){
                     if(maxi<rig-lef+1){
                    string t(s.begin()+lef,s.begin()+rig+1);
                    ans=t;
                    maxi=rig-lef+1;
                }
                    lef--;
                    rig++;
                }
               
                i++;
            
        }
        
        return ans;
    }
};