mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 21:41:08 +00:00
bfcb95b297
* fixup! Format Python code with psf/black push * Create codespell.yml * fixup! Format Python code with psf/black push
46 lines
1.1 KiB
Python
46 lines
1.1 KiB
Python
# Python program to implement Pigeonhole Sorting in python
|
|
|
|
# Algorithm for the pigeonhole sorting
|
|
|
|
|
|
def pigeonhole_sort(a):
|
|
"""
|
|
>>> a = [8, 3, 2, 7, 4, 6, 8]
|
|
>>> b = sorted(a) # a nondestructive sort
|
|
>>> pigeonhole_sort(a) # a destructive sort
|
|
>>> a == b
|
|
True
|
|
"""
|
|
# size of range of values in the list (ie, number of pigeonholes we need)
|
|
|
|
min_val = min(a) # min() finds the minimum value
|
|
max_val = max(a) # max() finds the maximum value
|
|
|
|
size = max_val - min_val + 1 # size is difference of max and min values plus one
|
|
|
|
# list of pigeonholes of size equal to the variable size
|
|
holes = [0] * size
|
|
|
|
# Populate the pigeonholes.
|
|
for x in a:
|
|
assert isinstance(x, int), "integers only please"
|
|
holes[x - min_val] += 1
|
|
|
|
# Putting the elements back into the array in an order.
|
|
i = 0
|
|
for count in range(size):
|
|
while holes[count] > 0:
|
|
holes[count] -= 1
|
|
a[i] = count + min_val
|
|
i += 1
|
|
|
|
|
|
def main():
|
|
a = [8, 3, 2, 7, 4, 6, 8]
|
|
pigeonhole_sort(a)
|
|
print("Sorted order is:", " ".join(a))
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|