Yet another C++ question

[Mayareira]

Hello everyone;

I've got a project that's asking me to input binary numbers and create a bunch of functions that'll print those binary, reverse them, shift to left and right and convert it into decimal.

I've managed to make the program print and reverse the numbers but I am a little lost on "shifting" the binary.

3. ShiftLeft
a. Shift the numbers in the array left (mimicking the shift left operator). Note: You will not use the
<< operator to do this. Remember to pad with 0’s. Only shift one spot per function call.
4. ShiftRight
a. Shift the numbers in the array right (mimicking the shift right operator). Note: You will not use
the >> operator to do this. Remember to pad with 0’s. Only shift one spot per function call.


I emailed prof. and she said;

"We are mimicking
one integer number by an 8 element array where each element holds a binary digit
making up that number... so if want to shift left, we simply need to move each
element in the array one space to the left."

So I guess calling the "shift left" function will turn 11001100 into 10011001 (or 567890 to 678905).

I wrote this ;

int left = 0;
int right = s-1;
while(left < right){
int temp = ar[left];
ar[left] = ar[right];
ar[right] = temp;
left++;
right--;
}

for reverse function and it works pretty good. Does anybody have an idea on how to handle this "shift left" thingy? I tried to store everything in temp and move them to left but...well, it failed. I suck at this thing :/

Thanks in advance for replies.

[Zarath]

Depends if he wants it to wrap or not, sounds like an in class assignment I did years ago lol.

Does he want u to code it like 11100000 to 11000000 or 11100000 to 11000001?

Easiest way probably for the former is just to allocate a temp array (with 8 slots), go though the original array from the 1-7, and tack a 0 at the end of the array that is being shifted left, if it's the latter, throw the original[0] into a temp variable and just tack it at the end.

[Mayareira]

Both. She is expecting a menu like;

1. Input Binary
2. Print Binary
3. ShiftLeft (one step to the left each time you call the function)
4. Shift Right (one step to the right this time)
5. Reverse
6. Convert

I coded menu, input, print and reverse but can't figure shift left and right ;_;

[Zarath]

I'm assuming that she expects you to just use "8 bit" binary data, and not have it compatable with any kind of data. I expect she also just wants you to shift it like the following.

11111111 to 11111110 for shift left

and

11111111 to 01111111 for shift right

which is essentially the >> and << operators when it comes to binary data. So essentially, what I believe basing off these assumptions, is that you just really have to allocate and populate a temp array and translate it to the original array, making sure that you tack on 0s where it deems necessary while not throwing numbers outside the array size.

[Jayhawk]

Gonna pseudocode this so I'm not blatantly giving you a solution. Only helping with shift right.

Shift Right:

let x = right-most index in array

loop until x = 2nd left-most index in array
   copy value in array[x -1] into array[x]
   x--;
end loop

set array[0] = 0

[Charla]

So I guess calling the "shift left" function will turn 11001100 into 10011001 (or 567890 to 678905).

That would be if it was a wrapping shift or padding with 1s, but you said it's padding with 0s, so that means 11001100 would shift left into 10011000, or shift right into 01100110. I don't remember whether that's a logical shift or an arithmetic shift.

As for implementation, Jayhawk appears to have the correct approach.

[Fhqwghads]

The correct approach is tell that bitch to get back in the kitchen and stop pretending she knows how to program.