Number System !!!

I want to do like this:

cin >> hex >> num;
cout << num ;
cout << dec << num;

cin >> oct >> n;
cout << n;

cin >> base(3) >> nnn;
cout << base(19) << nn;

What I have to do? Have you any code ???

You can search the board and probably find some reasonable approaches. When I did this I set up a system whereby I could convert any base to base 10 and then from base 10 to any base, but I'm sure there are different approaches.

I wrote an example program for this, but I don't have it here at work... I can post it this evening (California time).

The decimal, hex, octal input/output is easy using cout. There is a standard function for getting input in (almost) any base [strtoul() = string-to-long]. There is a non-standard function with the Microsoft compiler to display in (almost) any base... I don't remember what it's named.

Hello!

Code:

---

#include<iostream.h>
#include<iomanip.h>
#include<stdlib.h>
#include<string.h>

int main()
{
  char str[20];
  unsigned long int n;

  while(cin.getline(str,20))
  {
          if(str[0]=='0' && str[1]=='x')
      {
        char s[20];

        for(int i=2;i<strlen(str);++i)
                s[i-2]=str[i];

              n = atol(s);
        cout << dec << n << endl;
      }
      else if(str[0]=='-')
      {
              return 0;
      }
      else
      {
              n = atol(str);
        cout << "0x";
        cout << hex << n << endl;
      }
      str[0]=0;
      n=0;
  }

        return 0;
}

---

It was working but when the first segment converting hex to dec is not working as it only takes dec form and converts it to oct or hex. any suggestion. ???

>>n = atol(s);
That won't work. It only works for base 10. You're gonna have to write your own function to go from hex->decimal.

Here's a base converter I just threw together quickly. It can convert between bases 2-36.

Have fun! :)

This has a C example, but the strtol() function can be used in C++ too.