# Homework Help: Problem regarding C++

1. Oct 3, 2009

### semc

Write a C++ program that writes all binary sequences of length 15

Guys i have totally no idea how to go about doing this. Can anyone tell me how i should go about doing this?

2. Oct 3, 2009

### LCKurtz

Since 2^16 is the smallest integer using 16 binary bits how about writing n in binary with leading zeroes for n from 0 to 2^16 - 1 = 65535? Hopefully you don't have to print them.

3. Oct 3, 2009

### Hurkyl

Staff Emeritus
Write, by hand, all binary sequences of length 4.

Think about how you did it, devise an algorithm, Then implement it.

If you haven't figured out an algorithm, then try writing all binary sequences of length 5. If you still haven't figured out an algorithm....

Maybe, think about how you would give instructions to a six-year old that would allow them to write down all binary sequences of length 4. (without requiring them to understand what "binary" or "sequence" means)

4. Oct 3, 2009

### semc

Actually i only know some basic command like loop and arrays so am i able to do this base on them? I was thinking is there a way for the computer to convert ASCII into binary then i will just use a loop to get all the sequence?

5. Oct 4, 2009

### LCKurtz

The natural place to look would be the printf command. Unfortunately it doesn't have a built in binary converter, so you will have to roll your own. Which is likely the whole point of your assignment.

6. Oct 4, 2009

### Staff: Mentor

Not necesarilly - while function converting integers to ascii for a given radix is not a standard one, it is present in most C/C++ implementations.

But I agree that writing your own converter is a good exercise.

7. Oct 4, 2009

### semc

I bet its easier to teach a 6years old to write binary then to ask a comp to do it for me haha. Alright thx guys i will try to figure out the rest.

8. Oct 6, 2009

### semc

Guys i had written the program and the last term is 1000000000000000. I have one problem though, the question requires me to print 0 as 000000000000000 and the rest of the binary. How do i do that?

Last edited: Oct 6, 2009
9. Oct 6, 2009

### Staff: Mentor

This is a 16 bit sequence. Besides, calling it last doesn't tell anything, as we have no idea about how the numbers were ordered.

If your program correctly outputs everything as binary numbers, 000000000000000 is a correct binary form of 0.

10. Oct 6, 2009

### semc

So you mean for a binary sequence of length 15 the last binary will have 15 digits and not 16? Well i need to print out the zeros as stated in the question any idea how i can get the 1st term to be 000000000000000?

11. Oct 6, 2009

### Staff: Mentor

PHP:
printf("000000000000000");

12. Oct 6, 2009

### semc

Erm sorry but this only print 000000000000000 to the screen right? Because I wrote it in a way such that the nth term is calculated based on the (n-1)th term so i will need to print the 1st term as 000000000000000 in order for this to work. So is there any command to print them as string?

13. Oct 6, 2009

### Staff: Mentor

I am afraid I can't find any sense in what you have just posted. You sure you know what 'print' means?