Day 2 first part done, aoc 2020

advent_of_code/2020/2/src/main.rs

@@ -0,0 +1,67 @@
+use nom::{
+    bytes::complete::tag,
+    character::complete::{alpha1, anychar, multispace1, u32},
+    multi::separated_list1,
+    sequence::{preceded, tuple},
+    IResult,
+};
+
+fn parse_input(input: &str) -> IResult<&str, Vec<(u32, u32, char, &str)>> {
+    let (input, result) = separated_list1(
+        multispace1,
+        tuple((
+            u32,
+            preceded(tag("-"), u32),
+            preceded(tag(" "), anychar),
+            preceded(tag(": "), alpha1),
+        )),
+    )(input)?;
+
+    Ok((input, result))
+}
+
+fn solve_1(input: &str) -> usize {
+    let (_, input) = parse_input(input).unwrap();
+
+    input
+        .into_iter()
+        .filter(|(min, max, c, s)| {
+            let mut cs = 0;
+            for ch in s.chars() {
+                if ch == *c {
+                    cs += 1;
+                }
+            }
+
+            return cs >= *min && cs <= *max;
+        })
+        .count()
+}
+
+fn solve_2(input: &str) {}
+
+fn main() {
+    println!("Hello, this is Patrick!");
+
+    let input = include_str!("../input.txt");
+
+    let result_1 = solve_1(input);
+    println!("The number of valid passwords is {}", result_1);
+
+    let result_2 = solve_2(input);
+}
+
+#[cfg(test)]
+
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1() {
+        let test_input = include_str!("../test.txt");
+        assert_eq!(solve_1(test_input), 2);
+    }
+
+    #[test]
+    fn test_2() {}
+}