0347.前K个高频元素.md about rust

problems/0347.前K个高频元素.md

@@ -487,7 +487,34 @@ object Solution {
       .map(_._1)
   }
 }
+```
 
+rust: 小根堆
+
+```rust
+use std::cmp::Reverse;
+use std::collections::{BinaryHeap, HashMap};
+impl Solution {
+    pub fn top_k_frequent(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        let mut hash = HashMap::new();
+        let mut heap = BinaryHeap::with_capacity(k as usize);
+        nums.into_iter().for_each(|k| {
+            *hash.entry(k).or_insert(0) += 1;
+        });
+
+        for (k, v) in hash {
+            if heap.len() == heap.capacity() {
+                if *heap.peek().unwrap() < (Reverse(v), k) {
+                    continue;
+                } else {
+                    heap.pop();
+                }
+            }
+            heap.push((Reverse(v), k));
+        }
+        heap.into_iter().map(|(_, k)| k).collect()
+    }
+}
 ```
 
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