Added Day 2 Part 1 and it's input

small.input

@@ -1,6 +1,3 @@
-1721
-979
-366
-299
-675
-1456
+1-3 a: abcde
+1-3 b: cdefg
+2-9 c: ccccccccc

src/main.rs

@@ -1,28 +1,32 @@
-use std::collections::HashSet;
 use std::io::{stdin, Read};
 
 fn main() {
     let mut input = String::new();
     stdin().read_to_string(&mut input).unwrap();
 
-    let numbers: HashSet<u64> = input
+    let count = input
         .split('\n')
         .filter(|x| !x.is_empty())
-        .map(|x| x.parse::<u64>().unwrap())
-        .filter(|&x| x <= 2020)
-        .collect();
+        .map(|x| {
+            let mut x = x.split(':');
+            let policy = x.next().unwrap().trim();
+            let pwd = x.next().unwrap().trim();
+            let chars = policy.chars().last().unwrap();
 
-    'outer: for (i, &num1) in numbers.iter().enumerate() {
-        let diff = 2020 - num1;
+            let mut policy = policy.split_whitespace();
+            let limits = policy.next().unwrap();
 
-        for (j, &num2) in numbers.iter().enumerate() {
-            if i == j {
-                continue;
-            }
-            if numbers.contains(&(diff - num2)) {
-                println!("{}", num1 * num2 * (diff - num2));
-                break 'outer;
-            }
-        }
-    }
+            let mut limits = limits.split('-');
+            let lowerlimit = limits.next().unwrap().parse::<usize>().unwrap();
+            let upperlimit = limits.next().unwrap().parse::<usize>().unwrap();
+
+            (lowerlimit, upperlimit, chars, pwd)
+        })
+        .filter(|(lowerlimit, upperlimit, chars, pwd)| {
+            let count = &pwd.chars().filter(|x| x == chars).count();
+            count >= lowerlimit && count <= upperlimit
+        })
+        .count();
+
+    println!("{}", count);
 }