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Help needed for a first-year computer science exercise

SalaNsi -  

Hello,

I am in my first year of high school and I have a homework assignment that contains this exercise; I couldn't figure it out even after trying for a long time.

I have linked what I have completed along with the instructions.

Thank you!

7 answers

  1.  jee pee Moderator

    Hello,

    Rather than an image of the code, we prefer it to be in the message, with the source icon and the Python language which gives:

    for i in range(4): print(i)

    Your statement indicates that the power of 2 is a positional calculation from right to left, so you cannot simply take i. After that, you need to extract the position of the binary with a binary[i] syntax.

    1. SalaNsi Author

      I understand the code in the message, but after that I don't see how to do it from right to left, and even less how to extract the position of the binary since we haven't covered it in the course.

      1.  jee pee Moderator

        Depending on the value of i, from 0 to 3, you will extract the bit to be processed with binaire[i]

        Next, for the power of 2, you need to find a formula that combines i (varying from 0 to 3) and len(binaire) which equals 4 where

        • when i=0 power of 2 = 3
        • when i=1 power of 2 = 2
        • when i=2 power of 2 = 1
        • when i=3 power of 2 = 0
    2. SalaNsi Author

      I'm sorry, but even after searching for a long time, I still haven't found what needs to be put.

      1.  jee pee Moderator 
        int(binary[i]) * (2**(len(binary)-1-i))

        You need to take the Python course again.

    3. SalaNsi Author

      Thank you for that, but honestly I'm not lying to you, I have 3 other assignments in the homework and I don't know what the teacher has in mind, we don't have the course, he just gave us some tools to supposedly help us.

      2. SalaNsi Author

        I even started the 2nd exercise but I am still having difficulties

        here is the code for the 2nd and the instructions linked

        :

        def dec_to_bin(decimal):
        binary=""
        quotient = decimal // 2
        remainder = decimal % 2
        binary = remainder + binary
        while quotient!=0 :
        decimal = quotient
        remainder = decimal % 2
        binary = remainder + binary
        quotient = decimal//2


        # in the end, as long as the binary does not have a size of 4
        while len(binary) != 4:
        # we add "0"s to the left
        binary = ...

        return binary


        # The lines below test your code... don't touch them!
        # If an AssertionError appears... it means your code is not correct...
        assert dec_to_bin(10) == '1010'
        assert dec_to_bin(15) == '1111'
        assert dec_to_bin(0) == '0000'

        1. PierrotLeFou

          I didn't check if this site offers a Python course.
          Search for the site "Zeste De Savoir" the course "Zeste de Python" written by "entwanne".

          1. SalaNsi Author

            but actually I don't have much time because the assignment is due on Monday.