Added zero or one losses solution

README.md

@@ -112,6 +112,7 @@ other languages.
 - Design Bitset (https://leetcode.com/problems/design-bitset)
 - Minimum Rounds (https://leetcode.com/problems/minimum-rounds-to-complete-all-tasks)
 - Minimum Steps to Anagram (https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram)
+- Zero or One Losses (https://leetcode.com/problems/find-players-with-zero-or-one-losses)
 
 ### Other
 

src/leetcode/mod.rs

@@ -27,3 +27,4 @@ mod minimum_rounds;
 mod max_substr_between_duplicates;
 mod alike_halves;
 mod anagram_min_step;
+mod zero_or_one;

src/leetcode/zero_or_one.rs

@@ -0,0 +1,47 @@
+use std::collections::BTreeMap;
+
+fn find_winners(matches: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
+    let mut players = BTreeMap::new();
+    for m in matches {
+        if let [winner, loser] = m.as_slice() {
+            players.entry(*winner).or_insert(0);
+            *players.entry(*loser).or_insert(0) += 1;
+        }
+    }
+
+    players
+        .iter()
+        .fold(vec![vec![], vec![]], |mut acc, (player, losses)| {
+            match losses {
+                0 => acc[0].push(*player),
+                1 => acc[1].push(*player),
+                _ => {}
+            }
+            acc
+        })
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::leetcode::zero_or_one::find_winners;
+
+    #[test]
+    fn test_find_winners() {
+        let matches = vec![
+            vec![1, 3],
+            vec![2, 3],
+            vec![3, 6],
+            vec![5, 6],
+            vec![5, 7],
+            vec![4, 5],
+            vec![4, 8],
+            vec![4, 9],
+            vec![10, 4],
+            vec![10, 9],
+        ];
+        let winners = find_winners(matches);
+
+        let expected = vec![vec![1, 2, 10], vec![4, 5, 7, 8]];
+        assert_eq!(winners, expected);
+    }
+}