C code that reads input from analog pins on Beaglebone Black

analogIn.cpp

//Reference: Exploring BeagleBone - Derek Molloy
#include<iostream>
#include<fstream>
#include<string>
#include<sstream>
#include<unistd.h>
using namespace std;

#define LDR_PATH "/sys/bus/iio/devices/iio:device0/in_voltage"

int readAnalog(int number){
    stringstream ss;
    ss << LDR_PATH << number << "_raw";
    fstream fs;
    fs.open(ss.str().c_str(), fstream::in);
    fs >> number;
    fs.close();
    return number;
}

int main(int argc, char* argv[]){
    int AINnum;
    cout << "number of AIN pin (0-6) > " << endl;
    cin >> AINnum;
    if(AINnum < 0 || AINnum > 6){
           cout << "Invalid pin number!" << endl;
           exit(EXIT_FAILURE);
    }
    int value = readAnalog(AINnum);
    while (1) {
        value = readAnalog(AINnum);
        cout << "Input Value > " << value << " out of 4095." << " [Voltage: "<< ((float)value/(float)4095)*1.8 << "V]" << endl;
        usleep(1000000);
    }
    return 0;
}