Python/sorts/cyclesort.py
Sayan Bandyopadhyay 5d4471d35a
Update cyclesort.py
Changing for Python 3 using exception handling for robust code
2018-01-07 13:21:05 +05:30

61 lines
1.6 KiB
Python

# Code contributed by Honey Sharma
from __future__ import print_function
def cycle_sort(array):
ans = 0
# Pass through the array to find cycles to rotate.
for cycleStart in range(0, len(array) - 1):
item = array[cycleStart]
# finding the position for putting the item.
pos = cycleStart
for i in range(cycleStart + 1, len(array)):
if array[i] < item:
pos += 1
# If the item is already present-not a cycle.
if pos == cycleStart:
continue
# Otherwise, put the item there or right after any duplicates.
while item == array[pos]:
pos += 1
array[pos], item = item, array[pos]
ans += 1
# Rotate the rest of the cycle.
while pos != cycleStart:
# Find where to put the item.
pos = cycleStart
for i in range(cycleStart + 1, len(array)):
if array[i] < item:
pos += 1
# Put the item there or right after any duplicates.
while item == array[pos]:
pos += 1
array[pos], item = item, array[pos]
ans += 1
return ans
# Main Code starts here
if __name__ == '__main__':
try:
raw_input # Python 2
except NameError:
raw_input = input # Python 3
user_input = raw_input('Enter numbers separated by a comma:\n')
unsorted = [int(item) for item in user_input.split(',')]
n = len(unsorted)
cycle_sort(unsorted)
print("After sort : ")
for i in range(0, n):
print(unsorted[i], end=' ')