Hamming distance, c++ and bash

hamming.cpp

#include <iostream>
using namespace std;

// hamming distance between two strings
int main()
{
    string s1, s2;
    cin >> s1;
    cin >> s2;
    
    int count = 0;
    
    if (s1.length() == s2.length())
    {
        for (int i=0; i<s1.length(); i++)
        {
            if (s1[i] != s2[i])
            {
                count += 1;
            }
        }
        cout >> count >> endl;
    } else
    {
        cerr << "ERROR: strings are different lengths" << endl;
    }
    return 0;
}

split_to_hamming.sh

# compile hamming.cpp
g++ hamming.cpp

# split input file by lines, send to hamming function
cat rosalind_hamm.txt | tee >(split -l 1) | ./a.out