Function to_numeric 

pub fn to_numeric(key: &str) -> Vec<u8> 

Converts a string key into a numeric representation based on alphabetical order.

This function is commonly used to derive numeric keys for transposition ciphers. It assigns a rank to each character in the key based on its Unicode scalar value. If characters are identical, their original positions determine their relative rank.

Arguments

• key - The string slice to be converted.

Returns

A Vec<u8> where each element corresponds to the alphabetical rank (0-indexed) of the character at that position in the original string.

Examples

use old_crypto_rs::helpers::to_numeric;

let key = "ZEBRAS";
let numeric = to_numeric(key);
// A=0, B=1, E=2, R=3, S=4, Z=5
// Z (5), E (2), B (1), R (3), A (0), S (4)
assert_eq!(numeric, vec![5, 2, 1, 3, 0, 4]);