Initial commit

1 files changed, 41 insertions, 0 deletions

diff --git a/day1/src/main.rs b/day1/src/main.rs
new file mode 100644
index 0000000..f9b93ce
--- /dev/null
+++ b/day1/src/main.rs
@@ -0,0 +1,41 @@
+use std::env;
+use std::io::BufReader;
+use std::io::BufRead;
+use std::fs::File;
+use std::process;
+
+fn main() {
+  let args: Vec<String> = env::args().collect();
+  if args.len() != 2 {
+    println!("Wrong number of arguments. Provide just a file name.");
+    process::exit(1);
+  }
+  let filename = &args[1];
+  println!("Using file {} as input.", filename);
+  let f = match File::open(filename) {
+    Ok(file) => file,
+    Err(e) => {
+      println!("Failed to open file {}. {:?}", filename, e);
+      process::exit(1);
+    }
+  };
+  let file = BufReader::new(&f);
+
+  let mut diffs: Vec<i32> = Vec::new();
+  for line in file.lines() {
+    let l = line.unwrap();
+    let res = l.parse::<i32>();
+    match res {
+      Ok(value) => {
+        diffs.push(value);
+      }
+      Err(e) => {
+        println!("{:?}. l: {:?}", e, l);
+        process::exit(1);
+      }
+    }
+  }
+
+  let result: i32 = diffs.iter().fold(0, |acc, x| acc + x);
+  println!("{}", result);
+}