subnett

#include<iostream>
#include<string>
#include<math.h>
#include<sstream>
using namespace std;
class ipv_4
{
private:
    int ip_a1, ip_a2, ip_a3, ip_a4;
    char ip_class;
    int sub_no;
    int sub_bit;
    string default_subnetmask;
    string require_subnetmask;
    int unmasked_bit;
    int total_host;
public:
    ipv_4()
    {
        string ip_address;
        cout << "Enter the IP address: ";
        cin >> ip_address;
        int i = 0;
        string j = "";
        while (ip_address[i] != '.')
        {
            j = j + ip_address[i];
            i++;
        }
        ip_a1 = stoi(j);
        i++;
        j = "";
        while (ip_address[i] != '.')
        {
            j = j + ip_address[i];
            i++;
        }
        ip_a2 = stoi(j);
        i++;
        j = "";
        while (ip_address[i] != '.')
        {
            j = j + ip_address[i];
            i++;
        }
        ip_a3 = stoi(j);
        i++;
        j = "";
        while (ip_address[i] != '\0')
        {
            j = j + ip_address[i];
            i++;
        }
        ip_a4 = stoi(j);
        determine_class_subnetmask();
    }
    void determine_class_subnetmask();
    void display_class_subnetmask();
    void read_subnet();
    int find_no_bits_borrowed();
    void find_subnetmask();
    void display_require_subnet();
    void display_range();
};
void ipv_4::determine_class_subnetmask()
{
    if (ip_a1 < 128)
    {
        default_subnetmask = "255.0.0.0";
        ip_class = 'A';
        return;
    }
    if (ip_a1 < 192)
    {
        default_subnetmask = "255.255.0.0";
        ip_class = 'B';
        return;
    }
    if (ip_a1 < 224)
    {
        default_subnetmask = "255.255.255.0";
        ip_class = 'C';
        return;
    }
    ip_class = 'D';
    return;
}
void ipv_4::display_class_subnetmask()
{
    cout << "Class of IP address is: " << ip_class << endl;
    cout << "Default subnet mask is: " << default_subnetmask << endl;
}
void ipv_4::read_subnet()
{
    cout << "Enter no of subnets: ";
    cin >> sub_no;
}
int ipv_4::find_no_bits_borrowed()
{
    int i = 0;
    if (sub_no == 1)
    {
        return 1;
    }
    while (sub_no > pow(2, i))
    {
        i++;
    }
    return i;
}
string itos(int temp)
{
    stringstream ss;
    ss << temp << endl;
    return ss.str();
}
void ipv_4::find_subnetmask()
{
    sub_bit = find_no_bits_borrowed();
    switch (ip_class)
    {
    case 'A':
        unmasked_bit = 32 - 8 - sub_bit;
        total_host = pow(2, unmasked_bit);
        require_subnetmask = "255.";
        if (sub_bit > 0)
        {
            if (sub_bit >= 8)
            {
                require_subnetmask = require_subnetmask + "255.";
                if (sub_bit >= 16)
                {
                    require_subnetmask = require_subnetmask + "255.";
                    int remaining_bit = sub_bit - 16;
                    int x = 0;
                    int j = 7;
                    for (int i = remaining_bit; i > 0; i--)
                    {
                        x = x + pow(2, j);
                        j--;
                    }
                    require_subnetmask = require_subnetmask + itos(x);
                }
                else
                {
                    int remaining_bit = sub_bit - 8;
                    int x = 0;
                    int j = 7;
                    for (int i = remaining_bit; i > 0; i--)
                    {
                        x = x + pow(2, j);
                        j--;
                    }
                    require_subnetmask = require_subnetmask + itos(x) + ".0";
                }
            }
            else
            {
                int x = 0;
                int j = 7;
                for (int i = sub_bit; i > 0; i--)
                {
                    x = x + pow(2, j);
                    j--;
                }
                require_subnetmask = require_subnetmask + itos(x) + ".0.0";
            }
        }
        else
        {
            require_subnetmask = default_subnetmask;
        }
        break;
    case 'B':
        unmasked_bit = 32 - 16 - sub_bit;
        total_host = pow(2, unmasked_bit);
        require_subnetmask = "255.255.";
        if (sub_bit > 0)
        {
            if (sub_bit >= 8)
            {
                require_subnetmask = require_subnetmask + "255.";
                int remaining_bit = sub_bit - 8;
                int x = 0;
                int j = 7;
                for (int i = remaining_bit; i > 0; i--)
                {
                    x = x + pow(2, j);
                    j--;
                }
                require_subnetmask = require_subnetmask + itos(x);
            }
            else
            {
                int x = 0;
                int j = 7;
                for (int i = sub_bit; i > 0; i--)
                {
                    x = x + pow(2, j);
                    j--;
                }
                require_subnetmask = require_subnetmask + itos(x) + ".0";
            }
        }
        else
        {
            require_subnetmask = default_subnetmask;
        }
        break;
    case 'C':
        unmasked_bit = 32 - 24 - sub_bit;
        total_host = pow(2, unmasked_bit);
        require_subnetmask = "255.255.255.";
        if (sub_bit > 0)
        {
            if (sub_bit == 8)
            {
                require_subnetmask = require_subnetmask + "255";
            }
            else
            {
                int x = 0;
                int j = 7;
                for (int i = sub_bit; i > 0; i--)
                {
                    x = x + pow(2, j);
                    j--;
                }
                require_subnetmask = require_subnetmask + itos(x);
            }
        }
        else
        {
            require_subnetmask = default_subnetmask;
        }
        break;
    }
}
void ipv_4::display_require_subnet()
{
    cout << "Number of subnet bit: " << sub_bit << endl;
    cout << "Required subnet mask: " << require_subnetmask << endl;
    cout << "Number of unmasked bit: " << unmasked_bit << endl;
    cout << "Number of total host: " << total_host << endl;
}
void ipv_4::display_range()
{
    int total_subnet = pow(2, sub_bit);
    int x1, x2, x3;
    x1 = x2 = x3 = 0;
    switch (ip_class)
    {
    case 'C':
        for (int i = 0; i < total_subnet; i++)
        {
            cout << ip_a1 << "." << ip_a2 << "." << ip_a3 << "." << x1 << "------------->";
            x1 = x1 + total_host;
            cout << ip_a1 << "." << ip_a2 << "." << ip_a3 << "." << x1 - 1 << endl;
        }
        break;
    case 'B':
        for (int i = 0; i < total_subnet; i++)
        {
            if (i >= 1)
            {
                if (x1 == 255)
                {
                    x1 = 0;
                    x2++;
                }
                else
                {
                    x1++;
                }
            }
            cout << ip_a1 << "." << ip_a2 << "." << x2 << "." << x1 << "------------->";
            x1 = x1 + (total_host % 256);
            if (x1 > 255)
            {
                x2 = x2 + (x1 / 256);
            }
            x2 = x2 + (total_host / 256);
            if (x1 == 0)
            {
                x1 = 255;
                x2 = x2 - 1;
            }
            else
            {
                x1--;
            }
            cout << ip_a1 << "." << ip_a2 << "." << x2 << "." << x1 << "--------------------" << i << endl;
        }
        break;
    case 'A':
        for (int i = 0; i < total_subnet; i++)
        {
            if (i > 0)
            {
                if (x1 == 255)
                {
                    x1 = 0;
                    if (x2 == 255)
                    {
                        x2 = 0;
                        x3++;
                    }
                    else
                    {
                        x2++;
                    }
                }
                else
                {
                    x1++;
                }
            }
            cout << ip_a1 << "." << x3 << "." << x2 << "." << x1 << "------------->";
            x1 = x1 + (total_host % 256);
            if (x1 > 255)
            {
                x2 = x2 + (x1 / 256);
                x1 = x1 - 255;
            }
            x2 = x2 + ((total_host / 256) % 256);
            if (x2 > 255)
            {
                x3 = x3 + (x2 / 256);
                x2 = x2 - 255;
            }
            x3 = x3 + ((total_host / 256) / 256);
            if (x1 == 0)
            {
                x1 = 255;
                if (x2 == 0)
                {
                    x2 = 255;
                    x3--;
                }
                else
                {
                    x2--;
                }
            }
            else
            {
                x1--;
            }
            cout << ip_a1 << "." << x3 << "." << x2 << "." << x1 << "--------------------" << i << endl;
        }
    }
}
int main()
{
    ipv_4 device1;
    device1.display_class_subnetmask();
    device1.read_subnet();
    device1.find_subnetmask();
    device1.display_require_subnet();
    device1.display_range();
}