Check Palindrome

//Code:

#include <iostream>
using namespace std;

bool palindrome(string a)
{
    int i=0,j=a.size()-1;
    while(i<j)
    {
        if(a[i] != a[j])
        {
            return false;
        }
        i++;
        j--;
    }
    return true;
}

int main()
{
    string a;
    cout<<"Enter a : ";
    cin>>a;
    bool res = palindrome(a);
    cout<<(res? "Palindrome" : "Not a Palindrome");
    return 0;
}