rs: add “2225. Find Players With Zero or One Losses”

Signed-off-by: Matej Focko <mfocko@redhat.com>

rs/find-players-with-zero-or-one-losses.rs

@@ -0,0 +1,28 @@
+use std::collections::BTreeMap;
+
+impl Solution {
+    fn find_answer(counters: &BTreeMap<i32, i32>, key: i32) -> Vec<i32> {
+        counters
+            .iter()
+            .filter_map(|(&player, &losses)| if losses == key { Some(player) } else { None })
+            .collect()
+    }
+
+    pub fn find_winners(matches: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
+        let mut counters: BTreeMap<i32, i32> = BTreeMap::new();
+
+        for m in &matches {
+            let [win, lose, ..] = m[..] else {
+                unreachable!()
+            };
+
+            counters.entry(win).or_insert(0);
+            *counters.entry(lose).or_insert(0) += 1;
+        }
+
+        vec![0, 1]
+            .iter()
+            .map(|&c| Solution::find_answer(&counters, c))
+            .collect()
+    }
+}