There are only 10 types of people in the world: those who understand binary, and those who don't. -- Unknown
Converting Decimal to Binary
To convert decimal to binary:
- take your decimal number, n
- divide your number by 2 and save the dividend and remainder
- make the dividend your new number
- push the remainder onto a stack
- repeat this process until your number is 0
- pop all the numbers of the stack to create the binary number
Do this on paper. Stop to understand why the remainder will always be 1 or 0.
FYI: The above technique works with decimal to any base! Just change '2' to the base you want to covert to.
# Returns a binary string # you would never do this in a real program as Python has `bin(n)` def decimal2binary(n): nba =  # n as binary array div = n # dividend while div != 0: rem = div % 2 div = div // 2 nba.append(rem) # list comprehension to reverse array and join elements as a string return ''.join(str(i) for i in reversed(nba))
Day 10: Binary Numbers. 30 Days of Code. HackerRank.