1 files changed, 59 insertions, 0 deletions
diff --git a/2022/src/utils.rs b/2022/src/utils.rs
new file mode 100644
index 0000000..8230c69
--- /dev/null
+++ b/2022/src/utils.rs
@@ -0,0 +1,59 @@
+#![allow(unused)]
+use std::{fs::File, io::Read, str::FromStr};
+
+pub fn read_input() -> String {
+    let mut args = std::env::args();
+
+    let mut file = File::open(
+        args.nth(1)
+            .expect("first argument should be input filename"),
+    )
+    .expect("could not open input");
+    let mut out = String::new();
+    file.read_to_string(&mut out)
+        .expect("could not read input file");
+
+    out
+}
+
+pub fn max_n<T: Ord>(vec: &mut Vec<T>, n: usize) -> &[T] {
+    top_n_by(vec, |a, b| a > b, n)
+}
+
+pub fn top_n_by<T, F: FnMut(&T, &T) -> bool>(vec: &mut Vec<T>, mut f: F, n: usize) -> &[T] {
+    for _ in 0..n {
+        for i in 0..vec.len() - 1 {
+            if f(&vec[i], &vec[i + 1]) {
+                vec.swap(i, i + 1);
+            }
+        }
+    }
+
+    &vec[vec.len() - n..]
+}
+
+pub fn iter_pair<T>(mut i: impl Iterator<Item = T>) -> (T, T) {
+    (i.next().unwrap(), i.next().unwrap())
+}
+
+pub fn iter_triple<T>(mut i: impl Iterator<Item = T>) -> (T, T, T) {
+    (i.next().unwrap(), i.next().unwrap(), i.next().unwrap())
+}
+
+#[inline(always)]
+pub fn parse_num<T: FromStr>(string: &str) -> (T, &str)
+where
+    <T as FromStr>::Err: std::fmt::Debug,
+{
+    let count = string
+        .chars()
+        .take_while(|x| x.is_numeric() || *x == '-')
+        .count();
+
+    (string[..count].parse().unwrap(), &string[count..])
+}
+
+#[inline(always)]
+pub fn parse_static<'a>(exp: &'static str, source: &'a str) -> &'a str {
+    &source[exp.len()..]
+}