add day 5

day05/Cargo.lock

@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "day05"
+version = "0.1.0"
+dependencies = [
+ "md5",
+]
+
+[[package]]
+name = "md5"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae960838283323069879657ca3de837e9f7bbb4c7bf6ea7f1b290d5e9476d2e0"

day05/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "day05"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+md5 = "0.8"

day05/src/main.rs

@@ -0,0 +1,69 @@
+use std::io::Write;
+
+#[cfg(debug_assertions)]
+const INPUT: &str = "abc";
+#[cfg(not(debug_assertions))]
+const INPUT: &str = "cxdnnyjw";
+// const INPUT: &str = "abc";
+
+fn main() {
+    part1();
+
+    println!();
+
+    part2();
+}
+
+fn part2() {
+    let mut result = [' '; 8];
+
+    for i in 0_i64.. {
+        let s = format!("{INPUT}{i}");
+        let digest = md5::compute(s);
+
+        let result_string = format!("{:x}", digest);
+
+        if result_string.chars().take(5).all(|c| c == '0') {
+            let mut chars = result_string.chars();
+            let the_position = chars.nth(5).unwrap();
+            let the_char = chars.next().unwrap();
+
+            if ('0'..'8').contains(&the_position) {
+                let position = the_position.to_string().parse::<usize>().unwrap();
+                if result[position] == ' ' {
+                    result[position] = the_char;
+                    println!("{}", result.iter().collect::<String>());
+                }
+            }
+            if !result.contains(&' ') {
+                break;
+            }
+        };
+    }
+    println!();
+}
+
+fn part1() {
+    let mut result = vec![];
+    for i in 0_i64.. {
+        let s = format!("{INPUT}{i}");
+        let digest = md5::compute(s);
+
+        let result_string = format!("{:x}", digest);
+
+        if let Some(the_char) = result_string
+            .chars()
+            .take(5)
+            .all(|c| c == '0')
+            .then(|| result_string.chars().nth(5).unwrap())
+        {
+            print!("{the_char}");
+            std::io::stdout().flush().unwrap();
+            result.push(the_char);
+            if result.len() == 8 {
+                break;
+            }
+        };
+    }
+    println!();
+}