Rust for 2b; clean julia version

2018/02/julia/compare.jl

@@ -5,12 +5,11 @@ function main()
     open("../input/input.txt") do file
         for line in eachline(file)
             id = map(x -> x[1], split(line, ""))
-            match_count = length(id) - 1
             for other in ids
-                common = other .== id
-                if sum(common) == match_count
+                diff = other .!= id
+                if sum(diff) == 1
                     # Print what's in common.
-                    println(join(id[common]))
+                    println(join(id[.!diff]))
                     # No labeled break in Julia yet.
                     # See also: https://github.com/JuliaLang/julia/issues/5334
                     @goto done

2018/02/rust/compare/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "compare"
+version = "0.1.0"
+authors = ["Tom <[email protected]>"]
+edition = "2018"
+
+[dependencies]

2018/02/rust/compare/src/main.rs

@@ -0,0 +1,46 @@
+use std::io::{self, BufRead, BufReader};
+use std::fs::File;
+
+fn main() -> Try<()> {
+    let file = File::open("../../input/input.txt")?;
+    let mut ids: Vec<String> = Vec::new();
+    'lines: for line in BufReader::new(file).lines() {
+        // Count chars.
+        let id = line?;
+        'others: for other in ids.iter() {
+            let mut diff_index = -1;
+            for (index, (c0, c1)) in id.chars().zip(other.chars()).enumerate() {
+                if c0 != c1 {
+                    if diff_index >= 0 {
+                        // More than one different.
+                        continue 'others;
+                    } else {
+                        diff_index = index as i32;
+                    }
+                }
+            }
+            if diff_index >= 0 {
+                // If we get here, it's because we had only one different.
+                let (a, b) = id.split_at(diff_index as usize);
+                let c: String = b.chars().skip(1).collect();
+                println!("{}{}", a, c);
+                break 'lines;
+            }
+        }
+        ids.push(id);
+    }
+    Ok(())
+}
+
+#[derive(Debug)]
+pub struct Err {
+    pub message: String,
+}
+
+type Try<Value> = Result<Value, Err>;
+
+impl From<io::Error> for Err {
+    fn from(_: io::Error) -> Err {
+        Err{message: "io error".to_string()}
+    }
+}