You are given a lowercase alphabet string s, and an offset integer k. Replace every letter in s with a letter k positions further along the alphabet. Note: If the letter overflows past a or z, it gets wrapped around the other side.
Example 1
Input
s = “abc”
k = 2
Output
“cde”
Explanation
“abc” gets moved 2 positions to the right.Example 2
Input
s = “aaa”
k = -1
Output
“zzz”
Example 3
Input
s = “zzz”
k = 1
Output
“aaa”Explanation
The “z” gets wrapped to “a”
Simple Caesar Cipher (Rot) Algorithm in C++
Given the input is all lowercase characters, we can rotate and replace in place the original characters using O(N) time and O(1) space. The K has to be modulous by 26 and add 26 in case it is negative.
1 2 3 4 5 6 7 | string caesarCipherAlgorithm(string s, int k) { k %= 26; for (auto &n: s) { n = 'a' + (n - 'a' + k + 26) % 26; } return s; } |
string caesarCipherAlgorithm(string s, int k) {
k %= 26;
for (auto &n: s) {
n = 'a' + (n - 'a' + k + 26) % 26;
}
return s;
}You may want to look at other caesar ciphers for example: ROT47 Algorithm
String Cipher Algorithms
- Simple Vigenère Cipher in C++
- A Simple Atbash Cipher
- Simple Vertical Cipher Algorithm
- Caesar Cipher Algorithm in C++
–EOF (The Ultimate Computing & Technology Blog) —
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