day02

1 files changed, 31 insertions, 0 deletions

diff --git a/2020/day02/src/main.rs b/2020/day02/src/main.rs
new file mode 100644
index 0000000..574e1d7
--- /dev/null
+++ b/2020/day02/src/main.rs
@@ -0,0 +1,31 @@
+fn main() {
+    let mut sled_valids = 0;
+    let mut toboggan_valids = 0;
+    for line in include_str!("../input0.txt").trim().split("\n") {
+        let (rule, pswd) = line.split_once(": ").unwrap();
+        let (range, letter) = rule.split_once(" ").unwrap();
+
+        let letter = letter.chars().nth(0).unwrap();
+
+        let (lo, hi) = range.split_once("-").unwrap();
+        let lo: i32 = lo.parse().unwrap();
+        let hi: i32 = hi.parse().unwrap();
+
+        let count: i32 = pswd.chars().map(|c| (c == letter) as i32).sum();
+        if lo <= count && count <= hi {
+            sled_valids += 1;
+        }
+
+        let tobo: i32 = pswd
+            .chars()
+            .enumerate()
+            .map(|(i, c)| (i as i32 + 1, c))
+            .map(|(i, c)| (c == letter && (hi == i || lo == i)) as i32)
+            .sum();
+        if tobo == 1 {
+            toboggan_valids += 1;
+        }
+    }
+    println!("sled     valid passwords: {}", sled_valids);
+    println!("toboggan valid passwords: {}", toboggan_valids);
+}