Data commit

Task/Vigen-re-cipher/Rust/vigen-re-cipher.rust

@@ -0,0 +1,49 @@
+use std::ascii::AsciiExt;
+
+static A: u8 = 'A' as u8;
+
+fn uppercase_and_filter(input: &str) -> Vec<u8> {
+    let alphabet = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    let mut result = Vec::new();
+
+    for c in input.chars() {
+        // Ignore anything that is not in our short list of chars. We can then safely cast to u8.
+        if alphabet.iter().any(|&x| x as char == c) {
+            result.push(c.to_ascii_uppercase() as u8);
+        }
+    }
+
+    return result;
+}
+
+fn vigenere(key: &str, text: &str, is_encoding: bool) -> String {
+
+    let key_bytes = uppercase_and_filter(key);
+    let text_bytes = uppercase_and_filter(text);
+
+    let mut result_bytes = Vec::new();
+
+    for (i, c) in text_bytes.iter().enumerate() {
+        let c2 = if is_encoding {
+            (c + key_bytes[i % key_bytes.len()] - 2 * A) % 26 + A
+        } else {
+            (c + 26 - key_bytes[i % key_bytes.len()]) % 26 + A
+        };
+        result_bytes.push(c2);
+    }
+
+    String::from_utf8(result_bytes).unwrap()
+}
+
+fn main() {
+    let text = "Beware the Jabberwock, my son! The jaws that bite, the claws that catch!";
+    let key = "VIGENERECIPHER";
+
+    println!("Text: {}", text);
+    println!("Key:  {}", key);
+
+    let encoded = vigenere(key, text, true);
+    println!("Code: {}", encoded);
+    let decoded = vigenere(key, &encoded, false);
+    println!("Back: {}", decoded);
+}