Random generated number from user input range.

// Numbers are random generated from user inputted range.
// Results are both written to file and shown in console.
// Result file can be changed @ line 17
// By changing "xx.txt"

#include <cstdlib>
#include <iostream>
#include <iomanip> // setprecision library
#include <stdio.h> // printf library
#include <string>
#include <cmath>   // mathematical commands // pow() sqrt() abs() ..
#include <limits>  // cin.ignore(numeric_limits<streamsize>::max(),'\n');
#include <fstream> // File input and output.
#include <ctime>   // Time for random generator
using namespace std;

const char rezF[] = "3U.txt";

// used to find number of digits in a number (1000 = 4) to be used in setw()
template <class T>
int numDigits(T number)
{
    int digits = 0;
    if (number < 0) digits = 1; // remove this line if '-' counts as a digit
    while (number) {
        number /= 10;
        digits++;
    }
    return digits;
}

int main(int argc, char *argv[])
{
    // Range: [x;y]
    // a = (x + rand() % (y - x +1)) // Random numbers in range;

    // Variables
    int a;
    int x, y;
    int temp;
    int inputedRange;
    ofstream rf(rezF);

    cout << "Range in which random numbers will be generated? [x;y]" << endl;
    cout << "From: ";cin >> x;
    cout << "To:   ";cin >> y;
    cout << "" << endl;
    rf << "User selected range" << endl;
    rf << "From: " << x << endl;
    rf << "To:   " << y << endl << endl;
    inputedRange = numDigits(y);    // setting setw() range
    srand(time(NULL));              // Initializing random number @ time

    for (int i = 0; i < 10; i++)    // Rows
    {
        for (int j = 0; j < 10; j++)// Lines
        {
            a = (x + rand() % (y - x + 1));
            cout << setw(inputedRange) << a << " ";
            rf << setw(inputedRange) << a << " ";
        }
        cout << "" << endl;
        rf << "" << endl;
    }
    cout << "\nThe numbers have been put in a file.";

    // Ending
    cout << " " << endl;
    //system ("PAUSE");
    return EXIT_SUCCESS;
}