feat(04/2015): solve first part for example, but is slow

Author: manhunto

Cargo.toml

@@ -9,5 +9,6 @@ edition = "2021"
 aoc-client = "0.2.0"
 clap = { version = "4.5.21", features = ["derive"] }
 dotenv = "0.15.0"
+md5 = "0.8.0"
 regex = "1.11.1"
 itertools = "0.13.0"

src/solutions/year2015/day04.rs

@@ -1,10 +1,23 @@
 use crate::solutions::Solution;
+use md5::compute;
 
 pub struct Day04;
 
 impl Solution for Day04 {
-    fn part_one(&self, _input: &str) -> String {
-        String::from("0")
+    fn part_one(&self, input: &str) -> String {
+        for answer in 0u64.. {
+            // println!("{}", answer);
+            let hash = format!("{}{}", input, answer);
+            let digest = compute(hash);
+
+            let x = format!("{:x}", digest);
+            // println!("{}", x);
+            if &x[0..5] == "00000" {
+                return answer.to_string();
+            }
+        }
+
+        unreachable!();
     }
 
     fn part_two(&self, _input: &str) -> String {
@@ -18,6 +31,7 @@ mod tests {
 
     #[test]
     fn part_one_example_test() {
-        assert_eq!("0", Day04.part_one(""));
+        assert_eq!("609043", Day04.part_one("abcdef"));
+        assert_eq!("1048970", Day04.part_one("pqrstuv"));
     }
 }