read from file and fix bug which selected same winner again

.gitignore

@@ -1 +1,2 @@
 /target
+*.txt

src/main.rs

@@ -1,19 +1,47 @@
 use combinatorial::Combinations;
 
+const VOTE_SEPARATOR: &str = "- Vote Separator -\n";
+const ANIME_SEPARATOR: &str = " | ";
+const VALUE_SEPARATOR: &str = ",";
+
 fn main() {
-    let anime = [
-        "Hunter x Hunter",
-        "Steins;Gate",
-        "Fullmetal Alchemist: Brotherhood",
-        "Monster",
-        "Attack on Titan",
-    ];
-    let votes: Vec<&[usize]> = vec![&[0, 1, 2, 3, 4], &[1, 0, 2, 4, 3], &[1, 0, 2, 3, 4]];
-    println!("winners: {:?}", select_winners(&votes, anime.len(), 2));
+    let args: Vec<String> = std::env::args().skip(1).collect();
+    if args.len() != 1 {
+        eprintln!("ERROR: Expected one argument: filepath");
+        std::process::exit(1);
+    }
+
+    let data = std::fs::read_to_string(&args[0]).unwrap();
+    for vote_data in data.split(VOTE_SEPARATOR) {
+        let mut lines = vote_data.lines();
+        let animes: Vec<&str> = lines
+            .next()
+            .expect("Expected list of animes")
+            .split(ANIME_SEPARATOR)
+            .collect();
+        println!("animes: {animes:?}");
+        let votes: Vec<Vec<usize>> = lines
+            .map(|m| {
+                m.split(VALUE_SEPARATOR)
+                    .map(|v| {
+                        if v.parse::<usize>().is_err() {
+                            println!("Failed to parse value: \"{v}\"");
+                            std::process::exit(1);
+                        }
+                        v.parse().expect("Expected integer value")
+                    })
+                    .collect()
+            })
+            .collect();
+        println!(
+            "winners: {:?}",
+            select_winners(&votes, animes.len(), animes.len())
+        );
+    }
 }
 
 fn select_winners(
-    votes: &[&[usize]],
+    votes: &[Vec<usize>],
     candidate_count: usize,
     amount_of_winners: usize,
 ) -> Vec<usize> {
@@ -31,6 +59,8 @@ fn select_winners(
     let mut winners: Vec<usize> = Vec::new();
     for _ in 0..amount_of_winners {
         let winner = (0..candidate_count)
+            // Find new winners each time.
+            .filter(|c| !winners.contains(&c))
             .map(|c| {
                 (
                     c,
@@ -54,7 +84,7 @@ fn select_winners(
 
 fn single_election(
     (candidate_a, candidate_b): (usize, usize),
-    votes: &[&[usize]],
+    votes: &[Vec<usize>],
 ) -> ((usize, usize), usize) {
     let (mut a_votes, mut b_votes): (usize, usize) = (0, 0);
     for vote in votes {