8000 some algorithms in python by gleydson · Pull Request #34 · AllAlgorithms/python · GitHub
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Merged
merged 15 commits into from
Oct 4, 2018
Merged

some algorithms in python #34

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47c5571
Addition of playfair cipher in python
gleydson Oct 3, 2018
d1e0f31
Delete README.md
gleydson Oct 3, 2018
9b3d0b4
add caesar cipher
gleydson Oct 3, 2018
c72e0d0
add avl data structure
gleydson Oct 3, 2018
f968d5d
add binary search
gleydson Oct 3, 2018
61e849f
add hash table
gleydson Oct 3, 2018
706a959
add heap
gleydson Oct 3, 2018
062938f
add edit distance
gleydson Oct 3, 2018
7cfefed
add floyd warshall
gleydson Oct 3, 2018
62e8655
add bucket sort
gleydson Oct 3, 2018
d89e7d3
add selection sort
gleydson Oct 3, 2018
8823514
add quick sort
gleydson Oct 3, 2018
836c10f
Merge branch 'master' of github.com:gleydson/python
gleydson Oct 3, 2018
1765cfd
delete bucket_sort to fix merge conflicts
abranhe Oct 4, 2018
44ddbc3
delete quick_sort to fix merge conflicts
abranhe Oct 4, 2018
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Addition of playfair cipher in python
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@gleydson
gleydson committed Oct 3, 2018
commit 47c5571087d38b9dd19ec85bd1f74451c949e1f1
Empty file added ciphers/README.md
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146 changes: 146 additions & 0 deletions ciphers/playfair.py
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#!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys

# @Author: Gleydson Rodrigues

# ./playfair.py [encrypt/decrypt] key message


alphabet = "abcdefghijlmnopqrstuvwxyz".upper()

def vetorize(text):
listText = []
for letter in text:
listText.append(letter)
return listText

def normalizeMessage(text):
newText = []
text = text.upper()
text = text.replace(" ", "")
text = text.replace(".", "")
text = text.replace(",", "")
pos = 0
while pos < len(text) - 1:
firstLetter = text[pos]
secondLetter = text[pos + 1]
if firstLetter == secondLetter:
if firstLetter == "X":
newText.append(firstLetter)
newText.append("Z")
pos += 1
else:
newText.append(firstLetter)
newText.append("X")
pos += 1
else:
newText.append(firstLetter)
newText.append(secondLetter)
pos += 2
if pos < len(text):
if text[-1] == "X":
newText.append(text[pos])
newText.append("Z")
else:
newText.append(text[pos])
newText.append("X")
return newText

def createMatrix():
matrix = []
for i in range(5):
matrix.append([])
for j in range(5):
matrix[i].append("")
return matrix

def mountGrid(matrix, key, alphabet):
alphabet = vetorize(alphabet)
line, column, pos = 0, 0, 0
for letter in key:
line = pos / 5
column = pos % 5
if letter in alphabet:
alphabet.remove(letter)
matrix[line][column] = letter
pos += 1
while len(alphabet) > 0:
line = pos / 5
column = pos % 5
matrix[line][column] = alphabet.pop(0)
pos += 1
return matrix

def getIndex(letter, matrix):
for i in range(5):
for j in range(5):
if matrix[i][j] == letter:
return [i, j]

def encrypt(message, key):
matrix = mountGrid(createMatrix(), key, alphabet)
message = normalizeMessage(message)
messageEncrypted = ""
pos, line, column = 0, 0, 1
while pos < len(message) - 1:
firstLetter = message[pos]
secondLetter = message[pos + 1]
indexFirstLetter = getIndex(firstLetter, matrix)
indexSecondLetter = getIndex(secondLetter, matrix)
if indexFirstLetter[line] == indexSecondLetter[line]:
messageEncrypted += matrix[indexFirstLetter[line]][(indexFirstLetter[column] + 1) % 5]
messageEncrypted += matrix[indexSecondLetter[line]][(indexSecondLetter[column] + 1) % 5]
elif indexFirstLetter[column] == indexSecondLetter[column]:
messageEncrypted += matrix[(indexFirstLetter[line] + 1) % 5][indexFirstLetter[column]]
messageEncrypted += matrix[(indexSecondLetter[line] + 1) % 5][indexSecondLetter[column]]
else:
messageEncrypted += matrix[indexFirstLetter[line]][indexSecondLetter[column]]
messageEncrypted += matrix[indexSecondLetter[line]][indexFirstLetter[column]]
pos += 2
return messageEncrypted

def decrypt(messageEncrypted, key):
matrix = mountGrid(createMatrix(), key, alphabet)
messageDecrypted = ""
pos, line, column = 0, 0, 1
while pos < len(messageEncrypted):
firstLetter = messageEncrypted[pos]
secondLetter = messageEncrypted[pos + 1]
indexFirstLetter = getIndex(firstLetter, matrix)
indexSecondLetter = getIndex(secondLetter, matrix)
if indexFirstLetter[line] == indexSecondLetter[line]:
messageDecrypted += matrix[indexFirstLetter[line]][(indexFirstLetter[column] - 1) % 5]
messageDecrypted += matrix[indexSecondLetter[line]][(indexSecondLetter[column] - 1) % 5]
elif indexFirstLetter[column] == indexSecondLetter[column]:
messageDecrypted += matrix[(indexFirstLetter[line] - 1) % 5][indexFirstLetter[column]]
messageDecrypted += matrix[(indexSecondLetter[line] - 1) % 5][indexSecondLetter[column]]
else:
messageDecrypted += matrix[indexFirstLetter[line]][indexSecondLetter[column]]
messageDecrypted += matrix[indexSecondLetter[line]][indexFirstLetter[column]]
pos += 2
return messageDecrypted

def help():
print(
"./playfair.py [encrypt/decrypt] key message"
)

def main():
params = sys.argv[1:]
if len(params) == 0:
help()
elif params[0] == "encrypt":
key = params[1].upper()
message = params[2:]
print(encrypt("".join(x for x in message).upper(), key))
elif params[0] == "decrypt":
key = params[1].upper()
message = params[2:]
print(decrypt("".join(x for x in message).upper(), key))
else:
help()

if __name__ == "__main__":
main()
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