Function helper

Recursion/Code/palindrome.cpp:6–14

using namespace std;

int helper(string S, int start, int end){
    if (start>=end){
        return 1;
    }
    if(S[start]!=S[end]){
        return 0;
    }
    return helper(S, start+1, end-1);
}
	
int isPalindrome(string S)
{