mirror of
https://github.com/python/cpython.git
synced 2024-11-24 02:15:30 +08:00
1018fad6a4
Remove aliases from the C module. Always implement bisect() and insort() aliases in bisect.py Remove also the "# backward compatibility" command, there is no plan to deprecate nor remove these aliases. When keys are equal, it makes sense to use bisect.bisect() and bisect.insort().
93 lines
2.5 KiB
Python
93 lines
2.5 KiB
Python
"""Bisection algorithms."""
|
|
|
|
def insort_right(a, x, lo=0, hi=None):
|
|
"""Insert item x in list a, and keep it sorted assuming a is sorted.
|
|
|
|
If x is already in a, insert it to the right of the rightmost x.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
"""
|
|
|
|
if lo < 0:
|
|
raise ValueError('lo must be non-negative')
|
|
if hi is None:
|
|
hi = len(a)
|
|
while lo < hi:
|
|
mid = (lo+hi)//2
|
|
if x < a[mid]: hi = mid
|
|
else: lo = mid+1
|
|
a.insert(lo, x)
|
|
|
|
def bisect_right(a, x, lo=0, hi=None):
|
|
"""Return the index where to insert item x in list a, assuming a is sorted.
|
|
|
|
The return value i is such that all e in a[:i] have e <= x, and all e in
|
|
a[i:] have e > x. So if x already appears in the list, a.insert(x) will
|
|
insert just after the rightmost x already there.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
"""
|
|
|
|
if lo < 0:
|
|
raise ValueError('lo must be non-negative')
|
|
if hi is None:
|
|
hi = len(a)
|
|
while lo < hi:
|
|
mid = (lo+hi)//2
|
|
if x < a[mid]: hi = mid
|
|
else: lo = mid+1
|
|
return lo
|
|
|
|
def insort_left(a, x, lo=0, hi=None):
|
|
"""Insert item x in list a, and keep it sorted assuming a is sorted.
|
|
|
|
If x is already in a, insert it to the left of the leftmost x.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
"""
|
|
|
|
if lo < 0:
|
|
raise ValueError('lo must be non-negative')
|
|
if hi is None:
|
|
hi = len(a)
|
|
while lo < hi:
|
|
mid = (lo+hi)//2
|
|
if a[mid] < x: lo = mid+1
|
|
else: hi = mid
|
|
a.insert(lo, x)
|
|
|
|
|
|
def bisect_left(a, x, lo=0, hi=None):
|
|
"""Return the index where to insert item x in list a, assuming a is sorted.
|
|
|
|
The return value i is such that all e in a[:i] have e < x, and all e in
|
|
a[i:] have e >= x. So if x already appears in the list, a.insert(x) will
|
|
insert just before the leftmost x already there.
|
|
|
|
Optional args lo (default 0) and hi (default len(a)) bound the
|
|
slice of a to be searched.
|
|
"""
|
|
|
|
if lo < 0:
|
|
raise ValueError('lo must be non-negative')
|
|
if hi is None:
|
|
hi = len(a)
|
|
while lo < hi:
|
|
mid = (lo+hi)//2
|
|
if a[mid] < x: lo = mid+1
|
|
else: hi = mid
|
|
return lo
|
|
|
|
# Overwrite above definitions with a fast C implementation
|
|
try:
|
|
from _bisect import *
|
|
except ImportError:
|
|
pass
|
|
|
|
# Create aliases
|
|
bisect = bisect_right
|
|
insort = insort_right
|