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71 lines
2.0 KiB
Rust
71 lines
2.0 KiB
Rust
use std::io;
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pub struct ShiftedLetter {
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pub origin: char,
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pub shifted: char,
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}
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pub fn shift_alphabet(shift: i32) -> Vec<ShiftedLetter> {
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let mut shift = shift;
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let mut result: Vec<ShiftedLetter> = Vec::new();
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let mut alphabet: Vec<char> = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".chars().collect();
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let is_negative_shift = shift < 0;
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if is_negative_shift {
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alphabet.reverse();
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shift = shift.abs();
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}
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for (index, letter) in alphabet.iter().enumerate() {
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let mut shifted_index = (index as i32 + shift) as i32;
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if shifted_index > (alphabet.len() - 1) as i32 {
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shifted_index = (alphabet.len() as i32 - shifted_index).abs();
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}
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let shifted_letter = alphabet[shifted_index as usize];
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result.push(ShiftedLetter {
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origin: *letter,
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shifted: shifted_letter,
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});
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}
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return result;
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}
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pub fn caesar_cipher(string: &str, shift: i32) -> String {
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if shift == 0 {
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return string.to_string();
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}
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let shifted_alphabet = shift_alphabet(shift);
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let mut result = String::new();
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for letter in string.chars() {
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if letter.is_whitespace() {
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result.push(letter);
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} else {
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let mut found_letter = &shifted_alphabet[0];
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for shifted_letter in shifted_alphabet.iter() {
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if shifted_letter.origin == letter {
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found_letter = shifted_letter;
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break;
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}
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}
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result.push(found_letter.shifted);
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}
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}
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return result;
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}
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fn main() {
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let mut string = String::new();
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io::stdin()
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.read_line(&mut string)
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.expect("Failed to read `stdin` line.");
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let string = string.trim();
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let mut shift = String::new();
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io::stdin()
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.read_line(&mut shift)
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.expect("Failed to read `stdin` line.");
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let shift: i32 = shift
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.trim()
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.parse()
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.expect("Failed to convert `width` as an `i32`.");
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println!("{}", caesar_cipher(&string, shift));
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}
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