Palindrome

#include <iostream>
#include <algorithm>
#include <memory.h>
using namespace std;
int Palindrome(const string &s){
    int ret = 1;
    int len;
    for(int i=0;i<s.length()-1;i++){
        len = 0;
        while((i-len-1)>=0&&(i+len+1<s.length()) && s[i-len-1]==s[i+len+1])   ++len;
        ret = ret > (len<<1)+1 ? ret : (len<<1)+1;
        
        if(s[i]!=s[i+1])
            continue;
        len = 1;
        while((i-len)>=0&&(i+len+1<s.length()) && s[i-len]==s[i+1+len]) ++len;
        ret = ret > len<<1 ? ret : len<<1;
    }
    return ret;
}

int main(int argc, char** argv){
    const string s = "BANANA";
    cout<<Palindrome(s)<<endl;
    return 0;//정상종료시 반드시 0을 리턴해야합니다.
}