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#!/usr/bin/env python
# Challenge 120
#
# TASK #1 - Swap Odd/Even bits
# Submitted by: Mohammad S Anwar
# You are given a positive integer $N less than or equal to 255.
#
# Write a script to swap the odd positioned bit with even positioned bit and
# print the decimal equivalent of the new binary representation.
#
# Example
# Input: $N = 101
# Output: 154
#
# Binary representation of the given number is 01 10 01 01.
# The new binary representation after the odd/even swap is 10 01 10 10.
# The decimal equivalent of 10011010 is 154.
#
# Input: $N = 18
# Output: 33
#
# Binary representation of the given number is 00 01 00 10.
# The new binary representation after the odd/even swap is 00 10 00 01.
# The decimal equivalent of 100001 is 33.
import sys
def swap_bits(n):
out = 0
shift = 0
while n > 0:
if (n & 1) != 0:
out |= 2 << shift
if (n & 2) != 0:
out |= 1 << shift
n >>= 2
shift += 2
return out
n = int(sys.argv[1])
n = swap_bits(n)
print(n)
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