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Help needed for a first-year computer science exercise

SalaNsi Posted messages 13 Status Member -  
SalaNsi Posted messages 13 Status Member -

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 Posted messages 31886 Registration date   Status Moderator Last intervention   9 981
     

    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.

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  2. SalaNsi Posted messages 13 Status Member
     

    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.

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    1. jee pee Posted messages 31886 Registration date   Status Moderator Last intervention   9 981
       

      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
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  3. SalaNsi Posted messages 13 Status Member
     

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

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    1. jee pee Posted messages 31886 Registration date   Status Moderator Last intervention   9 981
        
      int(binary[i]) * (2**(len(binary)-1-i))

      You need to take the Python course again.

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  4. SalaNsi Posted messages 13 Status Member
     

    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.

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  6. SalaNsi Posted messages 13 Status Member
     

    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'

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  7. 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".

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  8. SalaNsi Posted messages 13 Status Member
     

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

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