def d_blockRotate(ciphertext, key):
# your code here
plaintext = ''
nonAlpha = get_nonalpha(ciphertext)
ciphertext = "".join([char for char in ciphertext if char.isalpha()])
blocks = text_to_blocks(ciphertext, key[0])
for i in range(len(blocks)):
blocks[i] = utilities_A2.shift_string(blocks[i], key[1], 'r')
#print(blocks[i])
temp = ''
for letter in blocks[len(blocks) - 1]:
if (letter != 'q'):
temp += letter
blocks[len(blocks) - 1] = temp
for block in blocks:
for j in range(len(block)):
plaintext += block[j]
plaintext = insert_nonalpha(plaintext, nonAlpha)
return plaintext
def e_blockRotate(plaintext, key):
# your code here
nonAlpha = get_nonalpha(plaintext)
ciphertext = ''
plaintext = "".join([char for char in plaintext if char.isalpha()])
blocks = text_to_blocks(plaintext, key[0])
for _ in range(len(blocks[len(blocks) - 1]), len(blocks[0]), 1):
blocks[len(blocks) - 1] += 'q'
for block in blocks:
ciphertext += utilities_A2.shift_string(block, key[1], 'l')
ciphertext = insert_nonalpha(ciphertext, nonAlpha)
return ciphertext
def getKeyL_shift(ciphertext):
# your code here
counts = [0] * 21
for i in range(1, 21):
s = utilities_A2.shift_string(ciphertext, i, 'r')
matches = 0
for j in range(i, len(s)):
if ciphertext[j] == s[j]:
matches += 1
counts[i] = matches
maxN = counts[0]
for num in counts:
if num > maxN:
maxN = num
k = counts.index(maxN)
return k
def d_blockRotate(ciphertext, key):
nonAlpha = get_nonalpha(ciphertext)
ciphertext = "".join([char for char in ciphertext if char.isalpha()])
blocks = text_to_blocks(ciphertext, key[0])
plaintext = ''
for block in blocks:
plaintext += utilities_A2.shift_string(block, key[1], 'r')
plaintext = insert_nonalpha(plaintext, nonAlpha)
index = 0
for i in range(len(plaintext) - 1, -1, -1):
if plaintext[i] != 'q':
index = i
break
plaintext = plaintext[0:index + 1]
return plaintext