Reverse bits of a positive integer number in Python
Given an positive integer and size of bits, reverse all bits of it and return the number with reversed bits.
Input : n = 1, bitSize=32 Output : 2147483648 On a machine with size of bit as 32. Reverse of 0....001 is 100....0. Input : n = 2147483648, bitSize=32 Output : 1
We can solve this problem quickly in Python. Approach is very simple,
- Convert integer number into it’s binary representation using bin(num) function.
- bin() function appends 0b as a prefix in binary representation of number, skip first two characters of binary representation and reverse remaining part of string.
- As we know in memory any binary representation of a number is filled with leading zeros after last set bit from left that means we need to append bitSize – len(reversedBits) number of zeros after reversing remaining string.
- Now convert binary representation into integer number using int(string,base) method.
How int() method wroks ?
int(string,base) method takes a string and base to identify that string is referring to what number system ( binary=2, heaxadecimal=16, octal=8 etc. ) and converts string into decimal number system accordingly. For example ; int(‘1010’,2) = 10.
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