day04 finished

src/common/file.rs

@@ -1,5 +1,27 @@
+use itertools::Itertools;
 use std::{fs, io};
 
-pub fn read_data(day_num: usize, file: &str) -> io::Result<String> {
+fn read_data(day_num: usize, file: &str) -> io::Result<String> {
     fs::read_to_string(format!("data/day{:02}/{}", day_num, file))
 }
+
+pub fn read_lines(day_num: usize, file: &str) -> io::Result<Vec<String>> {
+    let lines = read_data(day_num, file)?;
+    let x = lines
+        .split('\n')
+        .with_position()
+        .filter_map(|line| match line {
+            itertools::Position::First(line)
+            | itertools::Position::Middle(line)
+            | itertools::Position::Only(line) => Some(line.to_owned()),
+            itertools::Position::Last(line) => {
+                if line.len() == 0 {
+                    None
+                } else {
+                    Some(line.to_owned())
+                }
+            }
+        })
+        .collect();
+    Ok(x)
+}