1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
def sort(a):
"""Sort a list *IN PLACE*.
>>> a = [1, 1, 1, 1, 1, 2, 2, 1]
>>> sort(a)
>>> a
[1, 1, 1, 1, 1, 1, 2, 2]
>>> a = 'the quick brown fox jumped over the lazy dog'.split()
>>> sort(a)
>>> a
['brown', 'dog', 'fox', 'jumped', 'lazy', 'over', 'quick', 'the', 'the']
pre:
# must be a list
isinstance(a, list)
# all elements must be comparable with all other items
forall(range(len(a)),
lambda i: forall(range(len(a)),
lambda j: (a[i] < a[j]) ^ (a[i] >= a[j])))
post[a]:
# length of array is unchanged
len(a) == len(__old__.a)
# all elements given are still in the array
forall(__old__.a, lambda e: __old__.a.count(e) == a.count(e))
# the array is sorted
forall([a[i] >= a[i-1] for i in range(1, len(a))])
"""
a.sort()
# enable contract checking
import contract
contract.checkmod(__name__)
def _test():
import doctest, sort
return doctest.testmod(sort)
if __name__ == "__main__":
_test()
|
