y2016d5

y2016/Cargo.toml

@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+md5 = { workspace = true }

y2016/src/bin/d5.rs

@@ -0,0 +1,14 @@
+use y2016::days::d5;
+
+fn main() {
+    part1();
+    part2();
+}
+
+fn part1() {
+    println!("{}", d5::process_part1("ojvtpuvg"));
+}
+
+fn part2() {
+    println!("{}", d5::process_part2("ojvtpuvg"));
+}

y2016/src/days/d5.rs

@@ -0,0 +1,83 @@
+use std::io::{stdout, Write};
+
+pub fn process_part1(input: &str) -> String {
+    let mut password = String::new();
+    let mut n = 0;
+    let mut col = 1;
+    print!("________");
+    loop {
+        let hash = md5::compute(format!("{input}{n}"));
+        let hash = format!("{hash:x}");
+        let mut chars = hash.chars().skip(5);
+        let char = chars.next().unwrap();
+        print!("\x1b[{col}G{char}");
+        if hash.split_at(5).0 == "00000" {
+            col += 1;
+            password.push(char);
+        }
+        if password.len() == 8 {
+            println!();
+            return password;
+        }
+        n += 1;
+    }
+}
+
+pub fn process_part2(input: &str) -> String {
+    let mut password = vec!['_'; 8];
+    let mut n = 0;
+    print!("________");
+    loop {
+        if !password.contains(&'_') {
+            println!();
+            return password.into_iter().collect();
+        }
+        let hash = md5::compute(format!("{input}{n}"));
+        let hash = format!("{hash:x}");
+        if hash.split_at(5).0 == "00000" {
+            let mut chars = hash.chars().skip(5);
+            let position = match chars.next().unwrap().to_digit(10) {
+                Some(position) => {
+                    if position > 7 {
+                        n += 1;
+                        continue;
+                    }
+                    if password[position as usize] != '_' {
+                        n += 1;
+                        continue;
+                    }
+                    position
+                }
+                None => {
+                    n += 1;
+                    continue;
+                }
+            };
+            let char = chars.next().unwrap();
+            print!("\x1b[{}G{char}", position + 1);
+            //println!("{}", password.clone().into_iter().collect::<String>());
+            let _ = stdout().flush();
+            password[position as usize] = char;
+        }
+        n += 1;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const INPUT: &str = "abc";
+
+    #[test]
+    fn part1() {
+        let result = process_part1(INPUT);
+        assert_eq!(result, "18f47a30".to_string());
+    }
+
+    #[test]
+    fn part2() {
+        let result = process_part2(INPUT);
+        assert_eq!(result, "05ace8e3".to_string());
+    }
+}

y2016/src/days/mod.rs

@@ -5,3 +5,5 @@ pub mod d2;
 pub mod d3;
 
 pub mod d4;
+
+pub mod d5;