[DaleSeo] WEEK 01 Solutions

top-k-frequent-elements/DaleSeo.rs

@@ -0,0 +1,29 @@
+use std::collections::HashMap;
+
+// TC: O(n)
+// SC: O(n)
+impl Solution {
+    pub fn top_k_frequent(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        let mut freqs = HashMap::new();
+        for &num in &nums {
+            *freqs.entry(num).or_insert(0) += 1;
+        }
+
+        let mut buckets = vec![Vec::new(); nums.len() + 1];
+        for (num, freq) in freqs {
+            buckets[freq].push(num);
+        }
+
+        let mut top_nums = Vec::new();
+        for bucket in buckets.into_iter().rev() {
+            for num in bucket {
+                top_nums.push(num);
+                if top_nums.len() == k as usize {
+                    return top_nums;
+                }
+            }
+        }
+
+        top_nums
+    }
+}