Problem Set3(Caeser Cipher)

Q. In Caesar cipher, each letter is replaced by another letter which occurs at the  d-th position (when counted from the position of the original letter),  in the  English alphabet.  For identifying the position of a letter, we follow the usual order of the English alphabet, from a to z. Given a word and a positive integer d, use Caesar cipher to encrypt it. For example, if the word is 'ball' and the value of 'd' is 3 then the new encrypted word is 'edoo'. 'x' will be replaced by 'a', 'y' should be replaced by 'b' and 'z' should be replaced by 'c'. While the code is submitted for Online Judge (SkillRack), use rstrip(), to remove carriage return character in the input.

Input Format

Word

A positive integer 'd'

Output format:

Encrypted word

Input:

The word(word)

A positive number(number)

Processing:

word.rstrip()

number = int(input())

number = abs(number)

number = number%26

code = []

for i in range(len(word)-1):

    temp = ord(word[i])+ number

    if temp>122:

        temp = temp - 122

        temp = 96 + temp

        code.insert(i,chr(temp))

    else:

        code.insert(i,chr(temp))

Output:

Display the encrypted word

 

Algorithm:

Step1. Get the word from the user.

Step2. Remove the carriage from the word

Step3. Get a positive integer

Step4. Find the positive equivalent of the number if not positive

Step5. Change number as the remainder when number is divided by 26

Step6. Initialize code as an empty list and i as 0.

Step7. Repeat till i is less than length of the word

Step7.1 assign temp as ord(word[i]) + number ord() is used to covert the character in its decimal equivalent using ASCII or UNICODE conversions.

Step7.2 check if temp is greater than 122 if true proceed to 7.2.1 else move on to step 7.3

Step7.2.1 assign temp as the difference between temp and 122

Step7.2.2 assign temp as the sum of temp and 96

Step7.2.3 insert the character equivalent of temp in the ith index of code.

Step7.3 if temp is not greater than 122 then insert the character equivalent of temp at the ith index of code.

Step8. Display the encrypted code.

Program:

word = input()

word.rstrip()

number = int(input())

number = abs(number)

number = number%26

code = []

for i in range(len(word)):

    temp = ord(word[i])+ number

    if temp>122:

        temp = temp - 122

        temp = 96 + temp

        code.insert(i,chr(temp))

    else:

        code.insert(i,chr(temp))

for i in code:

    print(i,end='')

Issue:
If the expected output does not come then just change 'for i in range(len(word)):'
to for i in range(len(word)-1):

Flowchart:

To edit this flowchart click on this