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Simplify code by dropping support for legacy Python (#1143)

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* Simplify code by dropping support for legacy Python

* sort() --> sorted()
This commit is contained in:
Christian Clauss
2019-08-19 15:37:49 +02:00
committed by GitHub
parent 32aa7ff081
commit 47a9ea2b0b
145 changed files with 367 additions and 976 deletions
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29
searches/ternary_search.py
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@ -1,20 +1,13 @@
'''
This is a type of divide and conquer algorithm which divides the search space into
3 parts and finds the target value based on the property of the array or list
3 parts and finds the target value based on the property of the array or list
(usually monotonic property).
Time Complexity : O(log3 N)
Space Complexity : O(1)
'''
from __future__ import print_function
import sys
try:
raw_input # Python 2
except NameError:
raw_input = input # Python 3
# This is the precision for this function which can be altered.
# It is recommended for users to keep this number greater than or equal to 10.
precision = 10
@ -31,23 +24,23 @@ def ite_ternary_search(A, target):
right = len(A) - 1;
while(True):
if(left<right):
if(right-left < precision):
return lin_search(left,right,A,target)
oneThird = (left+right)/3+1;
twoThird = 2*(left+right)/3+1;
if(A[oneThird] == target):
return oneThird
elif(A[twoThird] == target):
return twoThird
elif(target < A[oneThird]):
right = oneThird-1
elif(A[twoThird] < target):
left = twoThird+1
else:
left = oneThird+1
right = twoThird-1
@ -57,7 +50,7 @@ def ite_ternary_search(A, target):
# This is the recursive method of the ternary search algorithm.
def rec_ternary_search(left, right, A, target):
if(left<right):
if(right-left < precision):
return lin_search(left,right,A,target)
@ -68,12 +61,12 @@ def rec_ternary_search(left, right, A, target):
return oneThird
elif(A[twoThird] == target):
return twoThird
elif(target < A[oneThird]):
return rec_ternary_search(left, oneThird-1, A, target)
elif(A[twoThird] < target):
return rec_ternary_search(twoThird+1, right, A, target)
else:
return rec_ternary_search(oneThird+1, twoThird-1, A, target)
else:
@ -87,7 +80,7 @@ def __assert_sorted(collection):
if __name__ == '__main__':
user_input = raw_input('Enter numbers separated by coma:\n').strip()
user_input = input('Enter numbers separated by coma:\n').strip()
collection = [int(item) for item in user_input.split(',')]
try:
@ -95,11 +88,11 @@ if __name__ == '__main__':
except ValueError:
sys.exit('Sequence must be sorted to apply the ternary search')
target_input = raw_input('Enter a single number to be found in the list:\n')
target_input = input('Enter a single number to be found in the list:\n')
target = int(target_input)
result1 = ite_ternary_search(collection, target)
result2 = rec_ternary_search(0, len(collection)-1, collection, target)
if result2 is not None:
print('Iterative search: {} found at positions: {}'.format(target, result1))
print('Recursive search: {} found at positions: {}'.format(target, result2))