y2024d9

y2016/src/bin/d6.rs

@@ -0,0 +1,20 @@
+use std::fs;
+
+use y2016::days::d6;
+
+fn main() {
+    part1();
+    part2();
+}
+
+fn part1() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/6_input.txt")).unwrap();
+    println!("{}", d6::process_part1(&content));
+}
+
+fn part2() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/6_input.txt")).unwrap();
+    println!("{}", d6::process_part2(&content));
+}

y2016/src/days/d6.rs

@@ -0,0 +1,73 @@
+use std::collections::HashMap;
+
+pub fn process_part1(input: &str) -> String {
+    let line_len = input.find("\n").unwrap();
+    let mut rows: Vec<HashMap<char, u32>> = vec![HashMap::new(); line_len];
+    input.lines().for_each(|line| {
+        for (idx, chara) in line.chars().enumerate() {
+            rows[idx]
+                .entry(chara)
+                .and_modify(|count| *count += 1)
+                .or_insert(1);
+        }
+    });
+    let mut res = String::new();
+    for row in rows {
+        let most_common = row.iter().max_by(|a, b| a.1.cmp(b.1)).unwrap().0;
+        res.push(*most_common);
+    }
+    res
+}
+
+pub fn process_part2(input: &str) -> String {
+    let line_len = input.find("\n").unwrap();
+    let mut rows: Vec<HashMap<char, u32>> = vec![HashMap::new(); line_len];
+    input.lines().for_each(|line| {
+        for (idx, chara) in line.chars().enumerate() {
+            rows[idx]
+                .entry(chara)
+                .and_modify(|count| *count += 1)
+                .or_insert(1);
+        }
+    });
+    let mut res = String::new();
+    for row in rows {
+        let most_common = row.iter().max_by(|a, b| b.1.cmp(a.1)).unwrap().0;
+        res.push(*most_common);
+    }
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const INPUT: &str = "eedadn
+drvtee
+eandsr
+raavrd
+atevrs
+tsrnev
+sdttsa
+rasrtv
+nssdts
+ntnada
+svetve
+tesnvt
+vntsnd
+vrdear
+dvrsen
+enarar";
+
+    #[test]
+    fn part1() {
+        let result = process_part1(INPUT);
+        assert_eq!(result, *"easter");
+    }
+
+    #[test]
+    fn part2() {
+        let result = process_part2(INPUT);
+        assert_eq!(result, *"advent");
+    }
+}

y2016/src/days/mod.rs

@@ -7,3 +7,5 @@ pub mod d3;
 pub mod d4;
 
 pub mod d5;
+
+pub mod d6;