C++ To ARM Assembly

Question

I'm tasked with writing code that will take a string and find the length of the string, and then proceeding to check if the string is a palindrome or not. I'm very new to ARM and very confused. I have the basics of checking for a palindrome in C++

#include <iostream>
using namespace std;

int main(){
    string s;
    cin >> s;

    int l = 0;
    int h = s.length()-1;

    while(h > l){
        if(s[l++] != s[h--]){
            cout << "Not a palindrome" << endl;
            return 0;
        }
    }
    cout << "Is a palindrome" << endl;
    return 0;

}

I would like to know where to start in this program as I find little on how to code in ARM.