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Wrap lines that go beyond GitHub Editor (#1925)

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* Wrap lines that go beyond GiHub Editor

* flake8 --count --select=E501 --max-line-length=127

* updating DIRECTORY.md

* Update strassen_matrix_multiplication.py

* fixup! Format Python code with psf/black push

* Update decision_tree.py

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
This commit is contained in:
Christian Clauss
2020-05-01 23:36:35 +02:00
committed by GitHub
parent bcaa88b26c
commit 6acd7fb5ce
19 changed files with 161 additions and 82 deletions
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17
dynamic_programming/bitmask.py
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@ -4,10 +4,9 @@ This is a Python implementation for questions involving task assignments between
Here Bitmasking and DP are used for solving this.
Question :-
We have N tasks and M people. Each person in M can do only certain of these tasks. Also a person can do only one task and a task is performed only by one person.
We have N tasks and M people. Each person in M can do only certain of these tasks. Also
a person can do only one task and a task is performed only by one person.
Find the total no of ways in which the tasks can be distributed.
"""
from collections import defaultdict
@ -25,7 +24,8 @@ class AssignmentUsingBitmask:
self.task = defaultdict(list) # stores the list of persons for each task
# final_mask is used to check if all persons are included by setting all bits to 1
# final_mask is used to check if all persons are included by setting all bits
# to 1
self.final_mask = (1 << len(task_performed)) - 1
def CountWaysUtil(self, mask, task_no):
@ -45,7 +45,8 @@ class AssignmentUsingBitmask:
# Number of ways when we don't this task in the arrangement
total_ways_util = self.CountWaysUtil(mask, task_no + 1)
# now assign the tasks one by one to all possible persons and recursively assign for the remaining tasks.
# now assign the tasks one by one to all possible persons and recursively
# assign for the remaining tasks.
if task_no in self.task:
for p in self.task[task_no]:
@ -53,7 +54,8 @@ class AssignmentUsingBitmask:
if mask & (1 << p):
continue
# assign this task to p and change the mask value. And recursively assign tasks with the new mask value.
# assign this task to p and change the mask value. And recursively
# assign tasks with the new mask value.
total_ways_util += self.CountWaysUtil(mask | (1 << p), task_no + 1)
# save the value.
@ -85,6 +87,7 @@ if __name__ == "__main__":
)
"""
For the particular example the tasks can be distributed as
(1,2,3), (1,2,4), (1,5,3), (1,5,4), (3,1,4), (3,2,4), (3,5,4), (4,1,3), (4,2,3), (4,5,3)
(1,2,3), (1,2,4), (1,5,3), (1,5,4), (3,1,4),
(3,2,4), (3,5,4), (4,1,3), (4,2,3), (4,5,3)
total 10
"""

6
dynamic_programming/edit_distance.py
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@ -2,10 +2,12 @@
Author : Turfa Auliarachman
Date : October 12, 2016
This is a pure Python implementation of Dynamic Programming solution to the edit distance problem.
This is a pure Python implementation of Dynamic Programming solution to the edit
distance problem.
The problem is :
Given two strings A and B. Find the minimum number of operations to string B such that A = B. The permitted operations are removal, insertion, and substitution.
Given two strings A and B. Find the minimum number of operations to string B such that
A = B. The permitted operations are removal, insertion, and substitution.
"""