Mercurial > hg > config

annotate python/example/factorial.py @ 912:5d9c08d2a090 default tip

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
nvm
author Jeff Hammel <k0scist@gmail.com>
date Wed, 01 May 2024 14:39:53 -0700
parents 47a434dd5068
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
784
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
1 #!/usr/bin/env python
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
2 """how many 0s are in a factorial"""
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
3
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
4 import argparse
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
5 import sys
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
6
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
7 def factorial(N):
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
8 """factorial of `N`"""
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
9 if N == 1:
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
10 return 1
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
11 return reduce(int.__mul__, range(2, N+1))
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
12
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
13 def factorial_zeros(N):
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
14 """how many 0s are in a factorial?"""
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
15
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
16 return N/5
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
17
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
18 def main(args=sys.argv[1:]):
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
19 """CLI"""
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
20
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
21 parser = argparse.ArgumentParser(description=__doc__)
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
22 parser.add_argument('N', type=int, nargs='+')
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
23 options = parser.parse_args(args)
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
24
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
25 # sanity
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
26 if any([i < 1 for i in options.N]):
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
27 parser.error("Input values must be >= 1")
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
28
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
29 for i in options.N:
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
30 f = factorial(i)
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
31 print f
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
32
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
33 if __name__ == '__main__':
47a434dd5068 example: factorial using reduce
Jeff Hammel <k0scist@gmail.com>
parents:
diff changeset
34 main()